[TesTVWhirl]

Was that not one of those things Channel 4 still held a copy of on 35mm in the early years for emergencies, just it was never actually used? Though going off what appears to be written on the film can in the thumbnail there, the particular version that has been scanned (or stuck in front of a phone camera) for that Tony Pritchett YT channel looks like it might have been put together for a showreel or competition at the SIGGRAPH conference in the US in 1983, which may be why it was needed on film there.