Oh, hush, IndyRob. 
For myself, the sprawling size of the pork piece has become part of the charm of the "sandwich" (note the double quotes, HEH). It's part of what it is. As for whether it is a loin or a tenderloin piece pounded out - eh, I suppose it might depend on the place and how thick a slice of tenderloin one starts out with? :-) I embedded a video on this "sandwich" back in this post here on this thread. ;-)
I've not infrequently eaten it entirely deconstructed - meaning I chomp away at the pork piece, picking up bits of the fixin's as I go along, with bites of the two halves of the bun as well, without ever actually "putting them together into a stacked sandwich". :-) Fine dining it is not - everything is done using my hands, with dips into ketchup and mayo and whatever else as desired, plus the fries and this and that - all eaten by hand. Fork & knife? Heaven forbid. Only certain politicians (and a certain billionaire) do such outrageous things.
Anyway, here's a really blurry pic of this pork tenderloin sandwich I had mid-way through when I *did* put the pieces together after chomping around the edges. :-) I didn't post it before because it WAS so blurry - but maybe it might be entertaining in the context of the discussion... :-)
Yes, that's my left thumb at bottom left.
