[andreyf]

It has? Can you give an example?

This is generating a custom GIF file on the server. It's most likely been done by someone somewhere before, but not something I've been both gaming and forum-ing for a little while.

[pluma]

This is roughly how early webcams worked. So, it's indeed not novel.

[minimaxir]

Gaming forums did generated JPEGs based on time/location (so they could troll you by telling you your IP, as was typical of the teenage demographic)

I have not seen a generated GIF before.

[scoot]

The Roxen [1] web-server had a much more advanced example of this for a site they produced for a watch manufacturer.

The watch on the home-page displayed the current time with moving hands that were behind reflective glass. It was a server rendered gif. (c) 1996 or '97.

[1] http://roxen.com - now an Enterprise / Newsroom CMS.