This might be old news, but not long ago I finally managed to find this one scene I saw as a kid which had always stuck with me.
It's an animated short from way back when. The premise (if you don't mind spoilers) is that a Sam Neill-looking animator is working on a film when things start to get "meta" and his identity becomes unmoored.
The short itself is
here, way at the end, but the pertinent scene begins
here.