This probably isn't the thing you mean, but your description kinda sounds like tessellating hills and its predecessor demons in imperfect search.
Ah, it was John's post I was thinking of; thanks! (Apologies to John for not remembering it was his writing, although I suppose mistaking someone's visual imagery on a technical topic for Eliezer's might be considered an accidental compliment :).)
I'm having trouble locating an old post about optimization daemons that I know I read at one point. I believe it was written by Eliezer. It featured a lot of visual imagery of the daemon steering the path of the model through parameter-space by e.g. forcing it through narrow paths towards low loss surrounded by walls of high loss. Does anyone know which post I'm remembering?