I think they are looking for a picture of your tank from an outside window, or a picture of the glow of your tank outside your house. Myteemouse, you may have to turn your lights on for a couple minutes to get the pic...I don't think it will hurt your reef, but that is totally up to you. My shot will be a glow from a basement window. My neighbors joke that I have a Kmart blue light special going everynight.