hi diramos, as far as i know there is no feature like that. and if you see any themes that implement it, i can sayt that only a gimmick. if you click share on photo share, it will share the album or portfolio or page instead not an single image. i have doing research about this. and i found that almost all themes that implement this kind of feature is doing it wrong. its not share the image.
if you see some plugin or something that can share photo on facebook or twitter as a single photo, let me know. i will take a look how its work and if i able, i will try to modify some code to make it possible work with the themes.