HP does a camera with a slimming effect.
It makes people look further away, and slightly older. It doesn't actually make them look thinner. But I suppose the point isn't that it works so much as it is that you're supposed to want it to work.
Funny how much stock we put in how we look in photos, isn't it? The camera and the mirror and the eye only capture something vaguely related to reality as is. And apparently there's enough market for photos that prove us thinner than we are that at least one focus group must have bought on to the whole idea. What would you use a fake thinner photo for? Are these things mostly going to be used by Weight Watchers (you know, motivation... this could be you in just 8 short weeks)?