Google's latest interactiveSpotlight Story has an unusual twist... namely, it's watching you. The Piggy VR experience uses six-degrees-of-freedom movement tracking to have a pig respond to your gaze as its namesake character is tempted by a cake. Stare at Piggy and the porcine protagonist will look back with annoyance, guilt or surprise while trying to distract you. Look away, however, and Piggy may give in to cravings. Yes, it's easy to make jokes about a Google story that tracks what you're doing , but it's a clever way of involving the audience without disrupting the narrative.