I'm fairly certain that the back portion converts to either a shelf or "visor" as well as laying flat to provide work space as shown. If I'm right, there are chrome struts that hang off the side of the stove and are used to prop up the shelf configuration.
A beach shack we used to rent from a friend's friend had the basic version of this stove, without the Grill-A-Vator. The shelf was always propped up on that one, and it was handy to have that extra surface in the tiny kitchen. If I had a stove like this, I'd probably have that shelf propped up all the time too.
