This morning it happened to be cycling through a series of pictures by the contemporary American photographer Gregory Crewdson. The way it works is that it displays each picture for a full three minutes before shuttling to the next one. You can change the amount of time each picture is permitted to be on the screen, but I left it at three minutes, which I think is the default setting, because three minutes seemed to me about how long a person should sit with a photograph or a painting and really look at it.