I have this horrifying image of some reclusive animatronic mad genius toiling away in his underground laboratory (mother's basement) month after month, tinkering with and fine tuning his creations until the night of this recording.
That is pretty much exactly how it is. This was all started by one guy who, sadly, removed all his videos from YouTube, but who basically bought a bunch of decommissioned Showbiz Pizza animatronics installations and then painstakingly learned how to reprogram them.