At the very beginning of the level, Crow's Nest, stand on the Arbiter's left and look at his head. His left eye will disappear and reappear numerous times. You can see straight through his head when it disappears. This happens to both of his eyes, but never at the same time. He will still behave as if he's looking at you with both eyes. Also, his eyes are meant to be orange with black slits instead of pure black.