Ann is attractive, but looks slightly anorexic. Most photographers emphasize the predominant qualities of their subjects. Ann happens to have very long legs, and the photographer emphasized this. No big deal.
Exactly, there is nothing wrong with the photograph. As you said subjects generally have no idea how they are going to look after shot. It's probably nothing more than her being surprised at seeing herself
My biggest gripe with the photo is the lighting they used - her skin color is awful.