No, that isn't what it was. These guys are in tubs with lids, no more than 6 inches deep. And they are lifting the top few inches of their bodies and running it around the lid of the tub upside down.
Just kind of twisting and turning and doodling around, upside down with their chins against the lid. Looks a LOT like what Stevie does when he's "in the zone".
Gale