[gearhead]

Mine is a bit different. The tin is at the very top of the cabinet and angled outward at the top. I was told that the tin is there to direct the airflow from the fans out the upper side vent. The certified crackerjack Dometic tech at my selling dealer tried to pull the bottom edge of the tin down to prevent heat from escaping around the bottom of it, and accumulating above it.
I would take a pic but it's in the repair shop trying to get the fridge to work.