Reflections are a great example of this. Real, calculated, reflections are a relatively new concept in videogames, but lots of old videogames are able to replicate this effect by creating an “upside down” world, with duplicates of everything, and reflective surfaces are actually windows peering into the upside-down. Its an OK facsimile, but requires specific conditions to be met and can’t be applied broadly
Hmm, feels like it’s missing stuff. Does disc go shiny side up or down?