I’m totally with you on this one. I can see the current head being a later replacement.
Although: Anubis had the body of a man, not a lion, so that theory is fucked. If there was a different original head, it was probably something else: a lion, or an eagle, or something; the ancients loved to mix up animal parts in their mythos, so roll a dodecahedron for what it could have been. Not one of the main Egyptian gods, though: those were all human-body, animal-head. Putting one of those on the Sphinx body makes absolutely no sense, and OP^OP^ is a garden-variety moron.
P.S. that silhouette also just looks like a Doberman, which is twice as dumb.