In Storyboard view, only the first frame of each clip in the edit sequence is displayed. Shuttle through the sequence by dragging the cursor across the bottom of any frame.
Storyboard view provides a quick overview of all the elements that go into a sequence and is useful for fast scene insertion, deletion, reordering, and picture-only editing.
(a) First frame of first clip (b) First frame of second clip
Image courtesy of Behavior Communications Inc., Das Werk