having studied media, I learnt to use photoshop as a result and also general make up tricks to use in my films. It's shocking what you can do with just make up, at the end of the day you would never wear that much normally as it's really caked on, but you can't see that when the model/actor is the other side of the camera.
What else is scary is that you used to be able to tell when things had been airbrused, but now with digital manipulation it's hardly noticable. They can trim love handles, make fat tummys thin, smooth out blotches, stretchmarks and scars and it doesn't even look fake to the untrained eye.
Good photography can make someone look good, but that is where they should draw the line.