In the age of digital photography this is obviously not true. Using tools like photoshop you can add this in and air brush things out and we've all see photos that look genuine that turn out to be fake.
A lot of these amendments are used to creat funny photos that many of us laugh about but there is a more serious side.
Everyday we are bombarded with images of "beautiful people" with looks and bodies that we aspire to. Adverts show these people and hint that buying their product will help us achieve this.
So do watch this New York Times video called Sex, Lies and Photoshop showing just how many of the images we see are "photoshoped". Rather disturbing I thought in this age where young girls getting eating disorders and have low self esteem over their bodies.
As the excellent The Online Photographer puts it.
The fine line between "you too could look like this (if you just buy our product)" and "you don't look like this (and you never will)."