This door is a smiling door. I wish it was being friendly but it is a term that means that your door has a 16 x 7 garage door loses its backbone support. The wood running along the sides of the door are held up metal hinges. Over time the the center of the door starts to buckle and sag over time, creating a “smiling” contour which will allow light to peer through the bottom of the door. You can see it in this picture .