They're labels. Ugly Girl is actually "The ugly girl," much like Queerboy would be "The queer boy," and so on. Someone decided to label them, and it stuck. And as they came to identify with their labels, their labels became their identity. It's like taking back the word.
Ruby Falls wrote:What do you think your label would be, Nanda?
In highschool, I fit a few of them, Ruby. Now? Uh... Depends on who you ask. Some would say "Purple-haired freak;" I've also been called a "Godless Liberal Feminist," which also depends on who you ask. My son has labeled me "Mommy," and I actually respect his opinion, so maybe I'll go with that.