Randomized Cassette Tapes

In Huang's Room Ryo has to find cassette tapes containing clues about Zhang's whereabouts.

Those tapes in the trashcan have a unique feature that hardly anyone is ever likely to notice.

While the amount and layout of the tapes always stays the same their textures are randomized each time you visit this place. This has no practical use whatsoever and is very easy to miss.
It only caught my eye when I was searching the room again and again in quick succession by reloading my save.

Five visits in a 5 second animation for your viewing pleasure

The tapes are randomized for this particular scene only. In the next scene you see them, where Ryo dumps them on the table in Ren's Hideout, they always land on it in the same arrangement.
Still, this crazy attention to detail is something that truly only Shenmue can pull off.