How does a girl get that "something about her"?

I've noticed, through the plethora of Rate Me/Am I Pretty/etc pictures on here, that most of the girls who post pictures have nice features. However, some of the girls have that "something about her" that makes her really pretty, while others (even though they have nice features) look kind of plain. I think I fit into the category of having nice features but still looking plain. How can I get that "something about me" that makes me look pretty? What is that "something", exactly?