The Royal Armouries, where it is displayed, has an informational page on the piece. Short answer is it probably wasn't intended to be Devil-ish at all, but rather a foolish, or jester-like, pageant piece rathern than field armour.

I think most people nowadays would probably agree that "Yep that looks terrifying," but that may not have been the case at all at the time. Without knowing what the rest of the harness looked like we're just looking at and judging the helmet in isolation and through a modern lense.