MovieGallery Icon    Setting the preview to another frame of the movie
 

You can change the preview (thumbnail) to another frame of the movie by:

1.

Select a movie by double-clicking it or change to media view by clicking the media view icon in the toolbar or press Command+3.

2.

Drag the movie-controller to the desired frame of the movie.

3.

Click the action-popup in the toolbar or ctrl-click the movie and choose Set preview To Current Frame.