This promotional photo of Jack Nicholson in the "Here's Johnny!" moment in The Shining was what got him cast as the Joker. In 1980, Michael Uslan, who would go on to executive produce all the Batman films, picked up a copy of the New York Post, and when he opened up the movie section, he saw this photo of Nicholson, which was advertising that The Shining was opening that weekend. Uslan, who had bought the film rights for Batman the year prior, immediately thought that Nicholson was the only one who could play the Joker. When he got home, he tore the photo from the paper and drew the Joker's face over it using Wite-Out and markers. The drawing, indeed, looks a lot like the Joker from the film:
Come to think of it...maybe its sophistication and useful knowledge is why no one else commented on this after being posted a full day ago...there's nobody to insult here.