It never happens when one of them has a strong negative reaction to the other person's looks. We see them more as tools to get objective information about someone's height, build, coloring, features, and style of dress – on the day the picture was taken, but that's all.
Someone you might find attractive in "real life" may not look good in a photo, because it distorts his features and doesn't reflect his inner qualities.
What really bothers me is having to send a photo to online dating sites.
A photo isn't the person – and for someone like myself who isn’t that photogenic, I make a much better impression face-to-face.
There isn't much you can do to change these preferences.