Hugh, For some reason I was able to place this link in your document in spite of the fact that you used that interesting editor. I wasn't able to get through to anyone else who used it--just one more of life's little mysteries.
I agree that there are quite a few interesting exercises that might be set up by having people alter the expected position of a reflective surface. We expect that a pool will be a horizontal reflecting surface. Altering that angle would be quite disconcerting I'll bet.
You have made a good point about the horse's off-the-ground position during full gallop, and there had been a very spirited debate before Muybridge's trip-wire photography settled the issue. I'm not sure though about your statement that "when we run we spend a large proportion of our time in the air'. Of course it depends what you mean by "large". The size of the running animal makes a big difference to this proportion, and an elephant, rhinoceros, or hippopotamus would not be able to provide the thrust necessary to escape ground contact. Humans certainly can and do, and watching competitive walkers, where there must be ground contact at all times, can convince us that running is quite a different matter. I wonder about the ground contact of smaller animals, like cats or mice? True hoppers like jackrabbits or kangaroos certainly spend an immense amount of time airborne. Interesting.
Your last comment seems to refer to a creative writing piece?