I like the concept. I love to look into the face and the eyes of my partner when he is having an orgasm. It is most certainly erotic for me and enhances MY orgasm.
I like the expressions of both men and women when they are at the peak of a sexual experience, either self induced or with a partner. Very arousing!
The site itself was somewhat disappointing because, in my opinion, many of the pictures appeared more posed and less spontaniously erotic. That's not to say there weren't a few that pulled me in and made my lower half contract.