It's not done yet -- I still need to "bless" most of the panels and give them timestamps, but it's pretty exciting to see it working:
video: [IMG_7695.m4v]
Each of the panels is simply an object whose name is a timestamp (like "0:39") and whose family is "seeing spaces panel":
When a panel is selected, a daemon on the poster responds by telling the wall to play the video from that timestamp.