Thinking more about hipping stones and what might be their opposite.
Hipping stones are for crossing small bodies of water while keeping your feet dry.
These ‘reverse’ hipping stones are for crossing the alley while keeping your feet wet.

The Stoneybrook alley proves to be reverse hippinable.
The action is (maybe, quite a guess here) tobi-mizu-kosaten?
addendum:
A slight alteration in the Japanese (many thanks, again, to a friend). ‘Tobi-mizu-hodou’ (jumping – water – pavement crossing) is a more correct way of phrasing the above (‘Kosaten’ implies a larger road or intersection).
also addendum:
Compiled these few bits and some additional history on a concrete wheels page.

otomo yoshihide
korekyojinn
haino, kawabata & yoshida
hilarious
and i love the japanese narrative
did you timer the pics or are these video stills?
Thanks.
[Camera, on a tripod, set to multiple frames
w/ assistant's finger on the shutter release.]
There may be alternate universes, and some may even be made from anti-matter — possibly our universe’s opposite — yet, you have, in your simple, backyard laboratory, have carried-out a remarkable experiment demonstrating the negative (in the anti- sense) behavior of a micro-anti-universe without benefit of quantum mechanics; a feat possibly deserving of submission for an Ig Nobel Prize. I offer your nomination. Are there seconds? Nice job, Jamie! Geoff
Thank you, Geoffrey.
“I feel with a federal grant I could make it a lot more silly.”