He is inside a huge armor. His head is not as big as the armor's head.
There is not even a hole made by the mind control device on the armor
This is when it was destroyed. See? No holes made by the device.
The armor is not a genetic part of him as well. He is just inside a prison armor made by his species because on his planet, he was a criminal.
So how was he being controlled? The headband wasn't even touching his head!