On a recent Friday afternoon, Emma Chamberlain passed a tow yard during a photo shoot in Beverly Hills. She walked by a row of dented sedans and sat on the step of a tow truck, her platinum mullet glowing white in the sun.

“Honestly, this is my enemy,” she said, eyeing the vehicle.

She told the story in the confessional, self-deprecating patter that helped make her one of her generation’s biggest YouTube stars: When she was 17 and had just moved to Los Angeles, she had made a critical parking error on a street-sweeping day in East Hollywood. The car was towed. She panicked.

“I just called my mom immediately,” she said. “Now, I think I’d know how to handle it, but back then I did not.”

A lot has changed since Ms. Chamberlain arrived in Los Angeles from the Bay Area six years ago, after leaving high school to focus on her vlogging career. At 23, she has 12 million subscribers on YouTube and 15 million followers on Instagram — more than Gwyneth Paltrow, more than Travis and Jason Kelce combined. She walks the red carpet at the Met Gala and sits in the front row at fashion weeks. When Charli XCX gathered a coterie of “it” girls for a music video this spring, Ms. Chamberlain was among them, checking her makeup in the rearview of a smashed-up S.U.V.