I know what you mean about the picture appearing to deteriorate, I quite often find that I like a picture on the day, but then a few days later I will look at it and see more male than before. I guess its down to it being a static point in time and being given the chance to scrutinize over and over noticing things, and once noticed they cant be over looked.
I think there is also the movement of goal posts as we get better at presenting. some pictures I took a few years ago I was really happy with at the time, but looking back at them now I just think, OMG Bad ->-bleeped-<- alert, and how did I ever get away with going out looking anything like that. Since those photos I have had a lot of self improvement, lost a lot weight, practiced makeup, etc., but at the time I thought they were great and was really happy that I looked good in them.
Although if I'm honest it was photos that played a major part in loosing the weight as for a while all that ever came out of the camera was a fat ugly man in a frock.