Actually from the site it looks like the digitized copies were saved as - get this - LaserDisc! Kudos to NYC, they decided to go full-on 80's mode for sure.
Indeed it is, but each frame presented here shows distortion consistent with being stored on a tape format at some point in time, definitely prior to LD mastering.
Yes, probably -- before digital cameras, there were still video cameras. They used a CCD to record still video images onto magnetic media such as a video floppy disk. So a lot like a digital camera, but fully analog.
These were pretty cutting-edge tech in the mid 80's and would have made a lot of sense for a project like this.
Oh yeah, plenty of cameras had a "photo" button, that recorded a single frame to like 2 seconds of VHS tape. You could put the tape into a reader, and project or print the photos later.