The Shutter Island poster uses several techniques to draw the audience in to see the film. The colour scheme of a dark blue and the rain gives the impression of fear and darkness. The island being out in the sea gives the impression of solitude and entrapment. The image reminds the audience of Alcatraz prison island, but it is much more sinister. The use of red catches the eye of the audience aswell and implies danger, blood.
The face of leonardo dicaprio takes up the majority of the poster not only as information for the audience but also an enticement using Star Theory.
The flame used above the lighthouse infuses the idea of darkness (as it is coming from a match) and this implies the film will be a thriller along with the other techniques used by the poster.
By saying the film is directed by Martin Scorcese would attract audiences who are aware of him.