
Here's a more plausible explanation from the yt comments..
I don't know all the ins and outs and the various people involved OR how the tech worked at the time, but roughly: A member of the production team will have prepared a shot list, planning cuts between the various cameras and zooming in etc to give a dynamic feel to the song, as was the fashion at the time. It wasn't all made up on the fly, I think this would have been prepared this at the rehersal. For example, it looks like at 21:05 we have shot 72, an arty zoom in by a camera into the keyboard player. For the live performance, the vision mixer needs to make all these cuts but they can't operate the desk and read from the shot list, so the PA (production assistant) is "calling the shots". They are counting to keep in time to the music, and to keep their place in the song, although at times this has gone out of the window due to all the fuss going on. She holds it together very well. Interwoven with the shot numbers are beats in bar 1, 2, 3, 4 so she knows where she is, but as muscians do, they will often count "*1*, 2, 3, 4, *2*, 2, 3, 4, *3*, 2, 3, 4, *4*, 2, 3, 4" so they can keep track of the bar and the beat. It looks like the shot 72 on the keyboard was planned to last 2 bars so she called "72.....(pause 3 beats) 2 (second bar), 2 (beat) , 3 (beat), 4 (beat), 73 (next shot, band in a line looking stoopid)". It seems a lot of the planning went out of the window and the vision mixer was guessing a lot of the time.
( , Wed 31 May 2023, 21:58, Reply)

I worked for a short time back with the old beeb of the C and it was when people thought it was "cool" to try and use video and visual effects in the same way that we used lighting effects in a nightclub. It required (along with many other things) some technical savy and indeed a feel for music (or at least the ability to keep time to the beat)
Nowadays its all computerised and controlled but then it was a bit of MIDI, some SMPTE codes and a lot of manual fading and switching using clunky controllers and more often that not some home made kit to keep it all together (in one instance we welded a massive iron bar on springs with little nipples (arf) that when pressed down would trigger multiple presses at once (for lights/smoke/confetti cannons etc) on a keyboard - itself most likely home made in a steel box that may or may not have been grounded - no idea how we got out alive now I think about it. Pyrotechnics controllers with the safety keys bypassed as they required a 3rd hand to use and there was never enough staff to go round so foot pedals for guitars would also be modified and used. Good times, if somewhat dodgy elf and safety wise :)
( , Thu 1 Jun 2023, 14:59, Reply)