A handheld display device for imaging a printed substrate and controlling playback of video associated with the printed substrate. The device comprises: an optical sensor for imaging an area of the printed substrate and for generating image data; a processor for determining interaction data using the image data, the interaction data identifying a substrate identity; a transceiver for retrieval of video data corresponding to part of the printed substrate; and a touch-sensitive display screen for displaying the video, or display information identifying the video, together with a static element for controlling video playback. Interaction with the static element via the touch-sensitive screen controls video playback.