To answer Serious Eats question about that: based on what I remember from the time I worked for the Scotsman, it is indeed an artifact of the burger construction process. Remember, you’re doing six Big Macs at a time; the cheese slice is put on the bottom piece of bread so that you know which ones are the bottom ones even after you’ve dumped Special Sauce, onions, and pickles on the whole thing. That makes it easier for the person actually assembling the burgers to box them quickly.
Pretty straightforward, really.
Moe Lane
Via… somebody.