Whip Pan Shot

Here is a short example of a whip pan shot from YouTube:



I believe this is a decent shot as it changed from two people having a conversation to someone enterning the door / scene. The shot looks as if it changes scene as it was light then it goes to dark and a light on when the girl enters.
A whip pan is usually used to show another object / person enter a room, or do something which could change the atmosphere of the scene.