Fake photographs have been around as long as photographs have been around. A widely circulated picture of Abraham Lincoln taken during the presidential campaign of 1860 was subtly altered by the photographer, Mathew Brady, to make the candidate appear more attractive. Brady enlarged Lincoln’s shirt collar, for instance, to hide his bony neck and bulging Adam’s apple. In a photographic portrait made to memorialize the president after his assassination, the artist Thomas Hicks transposed Lincoln’s...