Struck onto sats from the first Bitcoin transaction there has ever been — Satoshi to Hal Finney, 12 January 2009. Every one reads the live chain, performs what the block tells it to, and plays.
These are running right now. Nothing here is an image.
Right now
Everything below is being read off the live chain by the machine on the left. Nothing is scheduled and nothing repeats: the block picks it, and picks again in ten minutes.
How
Nothing about a piece is stored as a picture. One engine is inscribed once; every child is 127 bytes naming its sat. What you own is decided the moment the sat is chosen and never animates. What it does comes from the chain, and changes every ten minutes. The whole story is here.