Argument: None
Result: None
Valid for: Movie
Under MacOS, movies can have a 'poster' defined for them, i.e. a still picture which represents the movie. The Poster method causes this picture to be displayed. It the movie is running, it will be stopped first.
Under Windows and Linux, this method simply displays the first frame of the movie.
This method should not be used for a Movie with controller (style 0).