"It isn't perpetual motion until at the end everything is mechanically reset and the process starts over."

It sure seemed like it was ......... perpetual motion.

"In this video the energy was spent at each stage of the process (nothing was stored) and all energy was exhausted when the curtain opened."

There were times watching that video that I thought friction and rolling resistance should have brought that whole thing to a stop.  However, it just kept going......