Is it just my monitor, or my eyes - or do you also see random flickering pixels? I have no idea what could cause that - as far as I know the jpg format doesn't support animations. (And, if it was my monitor failing, then I'd imagine the flickering pixels would be everywhere, not just in this picture).

EDIT: I'm starting to think it is my monitor - for now I noticed flickering pixels on dark / blackish areas elsewhere, not just this picture. And this is not the laptop, but the desktop monitor of my main development machine.