About the Movie track
The global Movie track displays the opened QuickTime movie as thumbnails. If the Movie track is not visible, see Show and hide global tracks.
The number of frames displayed on the Movie track depends on both the track height and the zoom level of the window. All frames are aligned left, with only the very last frame aligned to the right. This guarantees that you can always see at least the first and last frames of video, independent of the current zoom level. Given the left alignment of all frames (except the last), the left margin of a frame is always displayed at the exact position of that particular frame.
Movie track and region settings can be adjusted in the Movie preferences window. See Movie preferences.