The clapperboard starts completely OFF-SCREEN on the far right.
It slides in from the RIGHT EDGE of the frame horizontally.
Moves left until it reaches the exact CENTER of the frame.
Stops. Makes ONE single clap.
Then slides back to the RIGHT, exits through the RIGHT EDGE
and disappears completely off-screen.
Direction of travel: RIGHT → CENTER → RIGHT.
Never moves left. Never exits left ...
