verb, to confuse the meaning or significance of an
entity by removing it from one
context, and
thrusting it into another
This is difficult to explain. It would be like walking into a hardware store and seeing a stack of garbage cans, nested inside each other, a price tag on each one. If you then reached into your mouth, located the piece of Juicy Fruit that lost its taste ten minutes ago, and threw it into the topmost can (because gum goes into the trash, duh!), that would be an instance of framejacking. Normally trash goes in the can, but when it's clearly on sale in a store...
I had a co-worker whose son (still in the process of being potty trained) wandered off while they visited a Home Depot. He returned shortly, and proudly proclaimed that he had gone potty, "Number two!" It then transpired that he had used one of the display models har har. Classic.