This is an interesting little video. This fellow put his iPad down on his MacBook Pro to answer a phone call (hmm) and observed the bizarre behavior shown above. Seems inexplicable, but the only explanation is that the MacBook thinks its lid is being closed. There must be some element of the iPad that reacts with the magnet or sensor that detects the MBP’s lid is shut. Probably something to be aware of if you’re a big Apple fanboy and often stack one Apple product on another.