I've noticed that I often look a lot worse in selfies than in other pictures. There's something about the perspective in selfies which makes me look less feminine.
That said, I once forwarded a selfie to a friend of mine, and asked her what she thought. She was at work, so she showed the image to a coworker and asked him "Do you notice anything different about this person?". The only thing he seemed to notice was my sidecut hair, and replied "Is she lesbian?"...
So basically, while selfies do look worse than other pictures, and (at least in my case) still pictures in general also often look worse than the live person, there is a dysphoric component to it, where sometimes even if you think you don't pass at all in a picture, people who don't know you may well not clock you if they see it.