You could check their profile pages on the Internet Archive Wayback Machine (archive.org). Image links are usually broken but you can tell from the URLs that the original model already had it in July 2012; a bit earlier if you check her profile under her previous model name. The most recent archive of the copycat profile from May 2013 doesn't show it -- she originally had something else.yossarian said:[...]
OK, but, how do we know which model came up with it first? I don't know either model (I mean, I've heard of the alleged plagiarist but never visited her room). Is it possible that the "original" model was actually the copycat?
Let's not jump to conclusions.
Besides, I waited until the original model contacted the copycat model *and* until the copycat model responded, since I wanted to give her the benefit of the doubt (hey, maybe she got someone else to do her profile). She admitted that she copied it, or as she calls it, "made it my own".
So no, I did not jump to conclusions.