facepalm

After your finger is nearly bit off by an electrical pig mincer, a tiny face appears in your hand. It seems to be tattooed on, at first. Repeated washings fail to remove it. The ink is deposited deep in your flesh. Knives, razors, fail to remove it.
It becomes like a reassuring mirror. You flex your palm to change it's neutral expression from vaguely malicious to somewhat sympathetic. After silently consulting it over and over again, it begins to develop a sort of sub-vocal speech. Like an invisible subtitle. "yes... yes" or "I sure wouldn't."