He notices the way she matches his posture and meets his eyes on a level, but apart from a brief flash of assertiveness, Spock takes this stance to mean that the Commander no longer views him as a threat.

"Indeed, I have many questions," he agrees, lowering himself back into his seat.
"My dealings with the Rihan have been necessarily limited, certainly at the point of time from which I was brought here, but I am curious to learn how you know of me."

He is thinking of the other female commander again, but knows the answer is probably temporal rather than personal.

"Have you been brought forward or back in time to this place?"