While the distribution of mass might quickly redistribute itself into a toroidal formation, internally, I think that area of effect (the fuzzy red zone in the diagram) would probably be pretty opaque to visible light. For a period of time, a gas cloud like that would probably have a really interesting appearance.

I'm imagining that, as the hot gases cool off, and condense onto floating debris, the molten/solid debris field will probably look pretty nebulous, and then settle into unstable bands. At that point, I figure the torus shape would be very apparent.

Once the hot gases were gone, I bet it probably took a while for the rest of the debris to get swept up into decaying orbits, and impact on either body (earth/moon).

If they could visualize it with a simulation, it'd probably be fun to watch, and tweak the parameters of the event.

That is shockingly fast.

Well, that's a comparatively small volume it covered in the grand scheme of things. Just think how quickly a bunch of hair and dust will clump together in the corner of an unswept room.