The only window I've seen is a plastic panel which is undamaged at one end and torn at the other. The wind probably tore it from its fixings. Would all passengers please replace their tin foil hats.
Given that the fixings in the bottom of the photo have hooks pointing up, I'd imagine that's the top. We can all rest easy knowing if we get bored on our next flight we know how to annoy the cabin crew by dismantling the interior of the aircraft.