In one implementation, a first captured image is accessed. The first captured image includes (1) a first display produced at a first point in time, and (2) a user interacting with the first display and not part of the first display. A second captured image is accessed. The second captured image includes (1) a second display produced at a second point in time, and (2) the user interacting with the second display and not part of the second display. The first captured image and the second captured image are compared. The motion of the user is determined based on a result of the comparing of the first captured image and the second captured image. The determined motion of the user is related to a portion of one or more of the first and second captured images.