When you are tasked with choosing a celebrity doppelgänger, you’ve got to keep egos in mind. “The choice reflects on the principal actor,” DeeDee Ricketts, the casting director for Titanic , told Vanity Fair in 2016. “We have to take into consideration that they can’t be too thin, or more beautiful, or too heavy, or too old, or else the principal actor will think, That’s how they see me?” Actors often get to give input on who will be their double, and sometimes have final approval rights written into their contracts . When she was being considered for the job of Janet Leigh's body double in Psycho' s iconic shower scene, model and Playboy covergirl Marli Renfro had to strip down for both Alfred Hitchcock and Leigh herself so that they could make sure her body looked enough like Leigh's, as Renfro recently revealed at a Brooklyn screening of the documentary 78/52: Hitchcock's Shower Scene . In the case of nude scenes, actors might even have final approval on what physical moves their doubles are allowed to make.