Oh that's a breaker box (or a box of wiring of some sort), not a mirror!

A mirror? I first saw it as a common (US-centric) exterior metal door, with a window -- and with a shelf blocking the opening.

The blur does interesting things.

	▲	cheschire 6 hours ago \| parent [-]
		yeah the shine in the top left of the rectangle was what led me to think it was a mirror, which from my experience would have been really strange for the types of nerds that would work in windowless rooms back in those days. The black cable underneath looked like the shadow of an oval frame