Yeah, the code looks like it determines based on what percentage of the image is "skin". The demo page gives a rather close-up shot of the upper-left of a woman's shoulders/chest. What if someone zooms out a little bit? In my tests it is not doing very well if the subject is not taking up the whole image.

Perhaps a better approach would be attempting to characterize certain features, like nipples/areola or buttocks. That definitely sounds like it would require more intensive processing, though, and be highly dependent on the angle of the image.

I don't really know much about image processing and computational analysis, I just like to pretend I know things.