"Um," Tadashi says, apparently unprepared for this question. "Well, I guess I'd say it's a trustworthy face. I assume you're not going for a 'might murder me in my sleep' kind of look, so it's probably a good one for you."

Since he's mostly submerged in water, he's actually taken off his power control gauntlet for once. It's sitting nearby in easy reach though, because he's not stupid.