It appears similar to prehistoric native american artifacts I have found. Maybe a broken knife. Cool find I think, but without more info like context in which it was found, part of the world, other lithic material present (you did not say but I guess it is stone), not much can be said about it. Hope you're going back and checking the place you found it closer, for more worked stone and maybe even the other half. And I would not read a whole lot into any perceived imagery in the piece. Probably accidental and not intended, but it did take a sharp eye to spot it.