Obviously anyone is free to judge anyone based on whatever criteria they want.

People are allowed to have whatever impression they want over something like anime pfps. That person who decides it's some crazy negative red light or whatever, just won't be my friend, which is fine. Sometimes people forget that not everyone has to be your friend.

Counterpoint: sometimes it's just a funny picture I like, and sometimes it's some anime titties I like. Assuming it's always going to be a meaningful representation of the user is unrealistic.

A lot of people don't treat it as such though, and thus it becomes odd to assume so. But some things are just downright questionable, obviously.