PiP and BOOBS are amusing acronyms for the facility to swap the position of WOW instances on the fly.

eg. I have a 1536x1200 main and 4 284x300 instance clones. They are configured with PiP hotkeys.

When I hit G2, bound the the hotkey for the first clone instance, it swaps the 384x300 instance into the 1536x1200 region (pre-configured in Keyclone) WoW automatically recognises that its screen area has changed and sets the resolution accordingly. Because the minis and main share the same aspect ratio (1.28 in my case) there is no stretching of the image.

The PiP hotkey has been set to the same keybinding as the macro which changes my group focus (and party leader)