He's disappointed for a moment but doesn't show it - his poker face is good for that, at least. He waits, and watches it again, doing his best to take in any details that didn't sink in the first time. When the figure with the rectangle appears-

"Wait. Stop. That right there - who is that?"

He points to the door, to the figure - he has no idea if this is going to translate at all, but it's worth trying.