When you opened a screen shot of a video in Paint, the video was playing in it

I made extensive use of this, when I found it by accident, in my Winamp skins and GUI programs!

This unlocked some memories. I remember on my system the chroma colour not being green but some very dark shade of grey that was almost black but not really black… something like #010101

I've used that trick as far as Windows XP, playing videos inside 3D models in programs like SketchUp