Well, when the shutter opens, the light passes through the lens and strikes the digital image sensor... Hehe, just kidding
Seriously, though, from the perspective of female body image, fashion and magazine photos are a major problem. The images are either heavily re-touched or complete composites, and this gives an unrealistic depiction at odds with how healthy women actually look. In the worst case scenario this can foster body image problems which could lead to death through eating disorders, substance abuse, or other similarly destructive behaviors.
If people are willing to blame media such as video games or movies for violent crimes, we should also accept the claim that fashion photography can destroy a person's self esteem. If you're not willing to go so far, it's at least important to recognize that fashion photography at large does not reflect reality, and this is another way that the fantasy of media is disjointed from how real people should actually live their lives.
I think it's a great idea for magazines to occasionally print untouched photographs side by side with the doctored version.