What we did get in the sandwich was a solid yellow rubbery mass. I recognize this thing; I've had it once before in some airport kiosk. It appears to be a precooked mass of egg so shaped to slide conveniently in between two pieces of bread. While I can forgive this in a situation with cramped cooking quarters, such as say, a airplane galley, a full restaurant should be ashamed to serve such a monstrosity. Never mind charging so much for it.
Funny thing, such "omelet cakes" can be done well. Notably, in Japanese cooking, where slices of carefully cooked slabs of egg can adorn nigiri sushi, and is a tribute to the skill of the chef.