I hate how people can be so critical and judgmental because of that criteria. I think most girls do it to one another because they're jealous that someone has something that they don't, even if it isn't clothes or objects. It could be friends and popularity as well. They also probably do it because they're being bullied and want to feel like they're cooler than someone else.
Because girls go into boy mode when they get together and we r perfectionist at heart. U have to learn not to listen or care what girls say or do in boy mode. As perfectionist it isn't easy to do but as we age and boy mode fades our perfectionism takes over and then save us from ourselves.