Apple Motion 4 - Manual (Page 80)

A tooltip appears to indicate the new In and Out point of the object, as well as the amount
of change from the previous position.
3 When you reach the position you want, release the mouse button.
To shorten or lengthen an object
1 Select the object to display it in the mini-Timeline.
2 Position the pointer over the beginning or ending edge of the object.
The pointer changes to a trim pointer.
Trim pointer Start of media
3 Drag the edge of the object to change its duration.
A tooltip appears to indicate the new In or Out point and the amount of change that
your edit is causing.
You cannot trim an object to be longer than the amount of frames available in the
corresponding media file unless its End Condition is set to Hold, Loop, or Ping Pong in
the Timing controls of the Properties tab of the Inspector.
To slip a video clip (or other multi-frame object) in the mini-Timeline
1 Select the multi-frame object you want to modify.
2 Position the pointer over the body of the clip in the mini-Timeline and press the Option
key.
The pointer changes to a slip pointer.
3 Drag the clip to the left or right to use a later or earlier part of the clip.
A tooltip appears to indicate the new In and Out points.
Slip pointer Start of media End of media
80 Chapter 2 The Motion Interface