Comment by drusepth

I've also wondered this, because I've considered setting one up for fictional creatures. If anyone has any details on the architecture of how these sites are set up.

I assume they generate a new image per time period [e.g. a second] and show the same image to everyone visiting the page rather than doing a generation per page load, simply because 1) they're so fast, and 2) sometimes if you refresh fast enough you can get the same image (at least one some TDNE sites). Would love to read some actual setup details though!