There are some Ancient Astronaut theorists that claim that this relief shows some type of ancient communication device (ancient Blu-Tooth). It's more than likely that it's really just a fancy earring or other decoration. Why would extraterrestrials, far advanced than us, use equipment that's identical to ours? Wouldn't they have something also far advanced? This phenomenon is a mistake AA theorists have made for decades now. Yeah, it's unsual, but not necessarily alien!