I don't see a difference as I move it. Is it doing something that I'm not seeing or does it do nothing? I'm confused by it - not sure if it's actually making changes that I can't see or if it's bugged.
Maybe there's more than one slider, I don't remember, but I know there's one that effects if the pattern is protruding from the skin, flush, or recessed. I would assume this effect only shows up if you have the right graphics settings turned on.