This is pure genius. Thanks to the indispensable Look at This for this one:
Younger (or older non-Brit) readers might like to know that in the distant past, when I was a lad[1] and so on, the few TV channels that we had did not run 24 hours a day, shocking as that may sound, and actually closed down for the night. Closedown time used to be quite early by current standards – 11pm or even earlier, except at weekends where showings of old horror movies might drag things on to midnight or even later.
Originally, they used to close down completely, leaving a white dot to burn itself into your CRT TV while playing a high pitched beeeeeeeep to try and alert viewers who’d fallen asleep in front of Play for Today or whatever it was. But in later years, they ran looped pages from the Teletext service. Teletext is what people used to turn to for breaking news and cheap holidays in those distant days BEFORE THE INTERNET. It was all a bit slow and a bit crap (rather like the internet in dial-up days), but it was good for quick news updates.
And that’s a lot of words to explain the quite sublime joke in the video. If you’re as old as me, you won’t have needed to read any of this, and probably didn’t..

