In the NHL, the refs are watching the timekeeper's box because there's a light that signifies when the commercials are done airing to let them know when to start the face off. You don't see it on TV, of course.All sports do this
When you are in the arena, during a TV commercial break, they play club music, put the camera on people in the audience and do stuff like the kiss-cam. Back in the day, they used to play organ music. Players just standing around on the ice, also waiting for the TV commerical light to go off.