Ah, thanks for your explanation re the gradient images, I got it, thanks! I think it does say that more or less in the text actually, I was understanding it a

Ah, thanks for your explanation re the gradient images, I got it, thanks! I think it does say that more or less in the text actually, I was understanding it a bit wrong, my bad. For me this preconditoning part of the article is the hardest to get an intuition for.