I believe the same technique was used with early "live webcams" too — utilising a quirk (or maybe it was an intentional feature) of the GIF format allowed the s

I believe the same technique was used with early "live webcams" too — utilising a quirk (or maybe it was an intentional feature) of the GIF format allowed the server to just "send more frames." I seem to recall GIF even allowed you to change the palette mid-animation for this purpose (although would love to know if there was any other purpose.) Had the side-effect of making it impossible to download the GIF as the server would never close the connection.