That is the pic I wanna see.
Yooper, Is the fan above that hole? There should be a hole for air to go into the fridge, and a return hole. One of them might have a shutter to regulate the air flow (regulated by the temperature dial there).
The fact that there is ice building up means you've got a defrost heater that isn't working the way it should, and/or you've got a drain hole that's clogged. I think you've found a symptom, not the source of the problem.