1. Only friends whom you know well comment on your pictures as to how "pretty" you are.
2. You've never/rarely had random Facebook guy friends you barely know or seen in passing comment how pretty you are.
3. The only guys capable of liking you are the ones who talk to you for a long time. (After you like someone's personality, the value of their facial aesthetics become trivial or you develop a junior fetish for the imperfections in their face.)
4. Interesting characteristic about people who are affected by DA is that they seem to band together. You'll often see these pseudo-pretty girls exchanging disingenuous compliments on each other's photos hoping deep down to get a "You're pretty too!" in return.
5. Have more than 80% of profile pictures with zero or few Likes from close associates with the occasional dressed up (birthday/homecoming/prom) photo with a higher-than-normal volume number of obligatory Likes.
6. When taking a picture of a possession or object, DAs have a compulsivity to feel the need to include their face in the photo. Comments are almost always about the object and rarely about the person's attractiveness.
Example of some girlfriends who suffer from Developed Attractiveness
*Rachel posts a photo of herself dolled up before going out to Club FZ*
Emma: Rachel! I love your dress! you look gorgeous
Rachel: Thanks Emma! you look beautiful in yours
See mermaid effect, mermaid syndrome, butterface