Thrawn didn't comment on others when they showed emotion. But since his vision also included the infrared spectrum he could plainly see the extra blood heating Dustin's face, it was still there even when he did finally turn around. He rarely commented on it but he always remembered it. Right now he still stayed entirely neutral and clasped his hands behind his back.

"I am afraid I do not know what 'funfronds' refers to. Could you please explain it?"