I’ve actually seen this with the naked eye when my kids hang slinkys off the loft:
What I found most interesting about this, is that it is more or less the same effect that made the collapse of the World Trade Centers look … so faked.
Yes, we all know that it wasn’t.
But, you have to admit that the video is not what you would have expected something like that to look like circa 9/10.
But, a building is very much like a slinky: a single structure, with some elasticity, being pulled down by gravity. The analogy is even closer if we view a single floor of the WTC as a slinky. And that odd, pancaking, effect as the floors collapsed was each of those slinkys compressing towards the base, and then sending its energy into the next slinky.