Obviously the meaning on this is all muddy, but here's what I could find with a little digging and it seems plausible "The pentacle of Satanism is an inverted pentagram, meant to represent the head of a goat (Satan is often portrayed in mythical drawings as a man with a goat's head.) The two upward-facing points are meant to resemble the horns of a goat, the sideways-facing points are ears, while the downward-facing point is the muzzle. Some schools of Satanism use the three downward-facing points to represent the rejection of the Holy Trinity of Christianity -- the Father, Son and Holy Ghost." Also, to note as somebody kindly pointed out, this is a pentacle, and not an upside down one like satanists would typically use, so it could either be very subtle, pagan in origin, or just our brains reading into things.