Olivia Rodrigo has been at the top of pop music since nearly the beginning of the year.

First there was “Drivers License,” Ms. Rodrigo’s runaway hit single, which inspired a viral TikTok challenge and topped the Billboard Hot 100 list for eight straight weeks. Then came “Sour,” her debut album, released in May to critical acclaim. Just last night an associated concert film, “Sour Prom,” began streaming on YouTube.

But last week, while promoting the film, Ms. Rodrigo, an 18-year-old former Disney star, hit one of the first public roadblocks of her breakout year: She was singled out by Courtney Love for a photograph promoting “Sour Prom.”

Ms. Love said that the photo, shot by Nick Walker, bore striking similarities to the cover of “Live Through This,” a 1984 album by Ms. Love’s band Hole. That photograph was taken by Ellen von Unwerth.

Both images feature distraught prom queens sporting tiaras and smudged eye makeup, and carrying congratulatory bouquets. Ms. Love reposted the “Sour Prom” image on Instagram with the caption “Spot the difference! #twinning!”

In the comments on Ms. Love’s Instagram post, Ms. Rodrigo responded “love u and live through this sooooo much.”

Ms. Love was not assuaged by the comment and appeared to expect an apology from Ms. Rodrigo. “Olivia — you’re welcome. My favorite florist is in Notting Hill, London! Dm me for deets! I look forward to reading your note!” she replied.

Ms. von Unwerth, a veteran fashion photographer whose work has earned her retrospectives around the world, said it isn’t unusual to see her images emulated by other artists.

“People copy all the time, they call it homage, but sometimes the copy is just too blatant and it is quite annoying,” she wrote in an email. “I actually tried to sue once, but it is very complicated and in the end not worth it. Today social media is doing the job.”

Mr. Walker, who photographed the “Sour Prom” image, did not respond to an interview request. A representative for Ms. Rodrigo declined to comment for this article.

Amy Adler, a professor at the New York University School of Law who specializes in art law, said that any legal action against Ms. Rodrigo for the image would be an “uphill battle.”

“You can’t copyright an idea, but only the expression of that idea,” she said.

Both images, Ms. Adler said, subvert “the smiling perfection of the idealized beauty queen.” It’s a common visual reference that predates the “Live Through This” cover; the prom scene from the 1976 horror film “Carrie” is probably the best known example, and Ms. von Unwerth herself has cited its influence on her own work.

Ms. Adler said that even though the images for “Sour Prom” and “Live Through This” carry out the same idea, they are still different enough that it likely wouldn’t be considered copyright infringement. Ms. Rodrigo, she said, could argue a fair-use case; making references to a copyrighted work or reproducing it can be legal, “if you’re using it for new purposes.”

Copyright law draws the line between protecting artistic expression and not letting people lock up ideas. “On the one hand, you don’t want to encourage people to steal other people’s expression,” Ms. Adler said. “But in its goal of encouraging and protecting creativity, copyright law also wants to leave room for creators to draw on previous works because so much creativity depends on the freedom to build on and reference previous works.”

While Ms. Love has requested flowers from Ms. Rodrigo, Ms. von Unwerth said she just would have liked to have been included. “I’d love to meet Olivia Rodrigo, I think she’s a wonderful young artist with a cool universe,” the photographer said. “I could offer my vision to the team and make a truly original project!”