The QuickTime Movie window is where Metro displays QuickTime movies. Metro syncs to the movie's time. You control the currently displayed frame of the movie with the arrow keys. Command-click in the movie window to reset the window to the default movie size. Click anywhere within the movie window to resize it.
Multiple video (movie) tracks are allowed. Video effects can be applied using zero, one or two sources. The destination movie for effects is always the first selected movie track.