LOL, I think those who can eat that outsize burger must have those expandable jaws similar to the kind that snakes have.
Here's the funny part: I grew up thinking a sandwich was two triangles of buttered bread, crust trimmed off, with a couple of slices of cucumbers or tomatoes as filling, or perhaps a little chicken. The sandwiches I saw in this great nation truly left me gobsmacked. I had the same question Howard asks above: How on earth do they eat them?
A similar revelation happened to me in reverse when I went to Italy and had their pizza for the first time: Conceptually, it was rather like my sandwich in India. A thin crust of dough with a bit of marinara sauce smeared on it and some melted cheese. Amazing, after consuming our American variety which is like a disc of dough with a small forest of toppings.
I suppose food reflects societies and cultures in interesting ways.
My Parents and I, we all ate Fried Chicken from the restaurant that My Father ordered from Ubereats, Texas Fried Chicken and it was delicious, despite the french fries, everything else was pretty good and greasy.