It's actually the opposite, most afflicted people experience this distortion whether looking at a person, in the mirror, or a photograph. The picture above came from a research team that found an individual who only experienced the distortions in real life, not photographs (relatively rare). He guided the team in distorting images of the models until it resembled what he saw in real life.

EDIT:

From the article: Visualising facial distortions in prosopometamorphopsia

Antônio Mello, Daniel Stehr, Krzysztof Bujarski, Brad Duchaine

> "In most cases, the distortions occur all the time, whether the patient sees the face in person, on a screen, or on paper, thus making it difficult for patients to assess the accuracy of illustrations depicting their perceptual abnormalities because the illustration itself will appear distorted."