One Friday afternoon, not long after unleashing the “Skims ultimate nipple bra” on the internet — a bra with a built-in erect nipple — and just before announcing that Skims was going to be the official underwear partner of the N.B.A., W.N.B.A. and USA Basketball, Kim Kardashian was sitting in her office in Calabasas, Calif., framed by two picture windows that offered views of manicured green lawns, and talking about size. Specifically, how big she wanted Skims to be.

“Sky’s the limit,” she said in a video interview. Her long hair was dark brown again, after another brief platinum period, and framed her face as neatly as the view outside. “I want to be in every country possible. I don’t really start out to do anything not the biggest possible.”

This is Kim the mogul. Kim, whose journey from sex tape to reality TV to Kanye West muse to billionaire businesswoman has been a speed trip through early-21st-century American culture. Kim the “emblem of American capitalism in the age of the social media economy,” as MJ Corey, a psychotherapist and the author of the coming book “DeKonstructing the Kardashians,” put it, taking yet another step on the march to world domination via Skims.

Founded four years ago, the brand went from being valued at $1.6 billion in 2021 to $4 billion last summer. In between, it became the official underwear outfitter of Team U.S.A. for the 2021 Tokyo Olympics, and won the 2022 Innovation Award from the Council of Fashion Designers of America. Last month, a men’s line was introduced.

Since the end of September, Skims has so dominated the social media conversation — first when Ms. Kardashian showed up at Victoria Beckham’s Paris fashion show 45 minutes late, then with its new campaign starring Cardi B, then by flooding the zone with half-naked male athletes like Neymar advertising undies, and then the nipple bra, sold with a tongue-in-cheek P.S.A. for climate change and in part to benefit a green nonprofit — that sometimes it seems as if Skims is single-handedly providing distraction in the otherwise overwhelming news cycle.

And now, it’s getting bedazzled.

Next week there will be yet another Skims collaboration (so many activations, so little time): a partnership with Swarovski, the Austrian crystal company known for its kitschy animals and rock star customizations. Effectively the first commercial salvo of the holiday season, it involves “body jewelry” — crystal-strewn belly and boob chains and necklaces — as well as crystal-encrusted mesh stretch dresses and bodysuits, one made-to-order dress composed of ginormous crystal strands, and various crystal-embedded separates in what the brand calls its Jelly Sheer fabric that recalls the Marilyn Monroe dress Ms. Kardashian wore to the Met Gala in 2022 and make you look naked and sparkling at the same time.

Thanks to the Swarovski connection, the line is going to go wide not just on social media, where Ms. Kardashian, with her 364 million Instagram followers, already reigns supreme. It’s also a play for dominance in the brick-and-mortar world, where it will be sold in 40 Swarovski stores around the world, including a new 14,400-square-foot New York store, which opens this month, as well as in special pop-ups in major department stores like La Rinascente in Milan, Galeries Lafayette in Paris, Lane Crawford in Hong Kong and the Mall of the Emirates in Dubai.

After the Skims 2021 collaboration with Fendi, it makes the case pretty clearly that Skims has transcended shapewear to become part of the bigger story of fashion today.

When Loungewear Becomes Evening Wear

“The best-kept secret about Skims,” said Jens Grede, the brand’s co-founder and chief executive, “is that our largest category of clothing is loungewear” — whatever “loungewear” means in a world in which categories of dress are getting evermore squishy, where leggings have pretty much been accepted as pants and comfort is key.

This year, Skims appeared on the Lyst index of “hottest brands,” ranked 17 out of 20 according to search in each of three quarters thus far. It is the only official non-high-fashion brand represented. (Nike, which used to be on the index, disappeared this quarter.) In the most recent listing, Skims was sandwiched between Louis Vuitton and Fendi, which is both a reflection of how people dress these days and the fact that Ms. Kardashian is, Ms. Corey said, “testing how high her ceiling can go.”

“We are all watching in real time, waiting for it to collapse,” she said, “but it never does.”

That’s the point of the Swarovski collaboration: “to stretch what the brand can do,” said Mr. Grede. “When we first launched Fendi, for example, we were very worried about the much, much higher-priced product. But it turned out that the highest-priced items sold out first.”

The collaboration is a low-risk way of testing the waters to see what the market will bear and laying the possible groundwork for more to come. Given that the brand has plans to open flagship stores next year in Los Angeles and New York, plus another five to eight in smaller cities, it’s hard not to see the Swarovski x Skims initiative as another way to test IRL retail.

Besides, this is not stuff that is meant to be kept under wraps. It’s meant to be worn out: to cocktail parties, dinner, date night, special occasions — anywhere someone might want to be “super fancy this season,” Ms. Kardashian said. This, despite the fact that “super fancy” is not a term that has traditionally been associated with Skims, which has largely been “super basic.” And despite the fact that Ms. Kardashian is careful to say she has no concrete plans for her own runway brand.

Still, she did acknowledge that winning the CFDA award “gave us a little bit of drive to do collaborations that were more high-fashion collaborations and branch off.” Also that “people wear our stuff as outerwear. All the time.”

And, Mr. Grede said, once you cover that stuff in crystals … well, “the lounge pieces really become evening dresses.”

Bedazzled

“I feel like it really embodies who I am, in being really simplistic, but then I have this full glitzy feminine side,” Ms. Kardashian said. She was modeling a strapless Skims Jelly Sheer bandeau top in nude that was speckled with crystals, like little winking stars, as if to demonstrate.

“I definitely evolved from the 2000s,” she said. “It’s been this taste journey that I have traveled through for the last decade, in all the things that I’m really interested in: architecture, landscaping. How I want my hedges cut isn’t too far off from how I want my packaging, with clean lines, very symmetrical. But as far as my crystallized things, I’ll always hold on to that. They just make me feel a certain way. I go to dinner at my mom’s, and everyone’s in pajamas, and I come in full Swarovski. That’s just who I am.”

This is why Giovanna Engelbert, Swarovski’s creative director, wanted to work with Ms. Kardashian. Though Swarovski has supported designers in the past by handing over crystals as raw materials, this is the first time the company has worked with a brand to co-create clothing that will be sold in its stores.

“We didn’t just want to make a crystal bra,” Ms. Engelbert said. She had worn Skims during her pregnancies and knew Ms. Kardashian in a vague way through fashion. She originally contacted her about two years ago, and they officially embarked on the project six months later, largely over group text. Ms. Kardashian calls them “think tank group chats.” (She and her team use the encrypted messaging app Signal so no one can steal the ideas.)

The partnership represents both “a new level of collaboration” and an expression of what Alexis Nasard, the Swarovski chief executive, said was a new business strategy built around “cultural relevance.”

“Kim’s persona and her visual codes are not in tune with everything else that you see,” he said. “Her styling also is not in tune always with everything that you see. There is a lot of originality in her, and in a way, she has been a cultural shaper.”

Ms. Kardashian, it turns out, has a history with crystals. “If I get a tooth gem,” she said, pointing at her mouth, “it has to be a Swarovski crystal. I used to make, like, little hair accessories and rhinestone things, and I’d have my glue — that E6000 glue — and a toothpick and the crystal, and I’d be bedazzling everything.” Her children have started to get her Swarovski figurines for Mother’s Day, like “a bear, you know, or a little Princess Jasmine. There’s certain things that just make you happy.”

One of the things that makes her happy is covering her laptop case in crystals. When she had a pink Apple MacBook, she covered it in pink crystals. When she had a black one, the sparkle was black. And now that she is back to silver, her Mac is frosted in silver Swarovski.

“I’d always had that idea of making outfits out of jewelry,” Ms. Kardashian said, adding that she wasn’t sure which of her new, jewelry-like outfits she would model at the opening of the Swarovski store on Fifth Avenue. “I have a few options that I pulled aside,” she said. “There’s two options I really love. I might just have to have a wardrobe change.”