Friends' relationship photography works

Don't infringe the copyright of your friend's photographic works. The other party just used an idea of your friend, and the idea itself cannot be protected by copyright law. You can ask the other party to stop the infringement in accordance with the provisions of the Anti-Unfair Competition Law.

Creativity, expressed in a specific form, constitutes the object of copyright protection and should be supported by the court.

I want to ask a question, please enlighten me: I have a friend who is a photographer. He created a group of portraits of ladies in the Tang Dynasty and published them in photographic publications, which gained a good reputation. A few days ago, he found that a photo studio printed a large number of brochures for the public using two photos he published, and claimed that the photos above were taken by their photo studio. My friend approached them and they took out the negatives of two photos in the brochure, claiming that they were not my friends. After careful comparison, the photos they used are consistent with the background, models, costumes, props and shooting angles of the works published by my friends, but the expressions of the models are slightly different. According to my friend's memory, he once developed photos in that studio, and they intercepted two of them. Because my friend took many photos from all angles, I didn't realize that there were two negatives missing. Now my friend can't find the model at that time, and I can't find the receipt of the studio. What I want to ask is, can my friend sue the studio for copyright infringement on the grounds that 99% of the photos used by the studio are consistent with the published works and all the other negatives taken from the same angle are in my friend's hands? How can my friend win the case? Please enlighten me!

Difficult!

If the evidence is sufficient, it should be supported by the court.