The state of being photogenic may or may not necessarily be related to one's physical attractiveness in real life. Models are usually described as photogenic. The bone structure of their faces may represent something that is not generally pretty or may be even a little ugly or frail looking, but when they are photographed, their features can turn into something that is physically attractive.
There are a few different possible causes for this. First, it's important to understand the difference between looking at someone with two eyes as opposed to through a single camera lens. With two eyes, the human brain is able to see the three dimensional aspects of someone's face, even when viewed directly from the front, and it gives much more information than most cameras. With a camera, the subject is viewed through a single lens, and thus much of the three dimensional qualities of the face are lost, and the face may seem narrower, less full, or with different proportions, especially when viewed at a close proximity. An interesting effect can be seen if one compares a close up picture of someone's face to a picture taken from twenty feet away from the same angle (particularly while directly facing the camera). The face will appear different in each picture, and the farther shot will give a better representation of the person's true three dimensional appearance.