Comparison shots of the not LIRR part—from when benches existed atop tblock glass tile in the mess of advertisements the station was toward its end. Over a few more photos, you see lockers. Then construction equipment. Then the back wall is suddenly missing. But it’s still clearly Old Penn Station.

(The block glass tile is still there; they just put boring airport floor over it.) Anyway, the character doesn’t really change until you get to where there’s a draped sheet pretending to be a ceiling, even though the benches haven’t moved. Then it’s just gone.