Ulquiorra simply raised an eyebrow at that. There were few people he considered superior to himself, and that was Aizen, Kurosaki Ichigo and the three Espada ranked higher than himself. Other than that, he didn't believe there was anything strong enough to take him down.
And according to observations so far, nothing in this place would be able to take him down.
"It's not a trick. Simply how I look when my true form is sealed."