Starting at 2:30 the music is timed perfectly with the banners. Certainly the machine's timing was not that precise. How they were able to keep it synced up? It's impressive that a machine that looks so rickety still works.
there are several instances of things being synced up. while it is probably true that they sped up and slowed down the video to make it match better, they still had to put effort into creating elements that would sync up, which is neat.