A new exhibit at the London Portrait Gallery sheds a great deal of light on the shady world of celebrity image-making. “The show takes 10 of the most familiar faces from the photographic age, from Queen Victoria to Gandhi to Greta Garbo and Adolf Hitler, and shows how they manipulated their images in order to further their aims, whether political or artistic or megalomaniacal.” The show also points up the media’s complicity in such makeovers, noting that many celebrity photos meant to look candid were, in fact, entirely staged.