I’m not on facebook. The whole idea of it seems odd, especially when I can put anything I want online on a web site if I have to.
However, I’m not sure that the implication of “people post pictures of themselves and other people say they look beautiful” is that their self worth is tied up in their appearance.
My thought is this. If someone posts their picture on facebook, nobody is going to say “wow, you look intelligent” or “you look like you have good values.”
Furthermore, would you really expect anyone to post “Wow, you have really let yourself go. Ever hear of a makeover ?”
From a statistical sampling point of view, this is a biased sample, not worth drawing conclusions from.
This isn’t to say that Facebookers aren’t fishing for compliments.