The prettiness or beauty you see in someone only after seeing their face for extended periods of time. These people aren't regarded as attractive by the masses, which is what real superficial attractiveness is. People who are lucky enough to even be affected by developed attractiveness can tell if they're one of them by using these guidelines.
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.
7. After dressing up nicely to go out on the town, DAs (or anyone else for that matter) will look much better than usual. They confuse this with actual attractiveness and take a mirror shot of themselves and post it to get cheap Likes and/or comments.
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