what the hell is girl #2 doing? (probably nsfw)

I came across this photo on the Net and just have to ask the readers… Can anyone explain WTF the girl in the back is doing? It’s especially interesting considering the guy is holding a camera and there is also one on the ground.

Does the babe in purple have a camera too?

Could this be a very elaborate coordinated attempt at an upskirt photo?

Is she a prostitute?

What are your thoughts?