Sasuke's gaze immediately shot back to Itachi. He was still for a moment, eying the Queen to see whether he was actually threatening him or just trying to act superior. The older Uchiha was completely pissed off as far as he could tell, tense even. This was new. Nothing ever got to Itachi; and if it did, the older had barely let it show. Maybe an annoyed quirk of the brow or a bemused glare. Even then, Sasuke generally knew what he'd done. This was understandable, as most of the things to Cat said to him were meant to try and set him off. He just hated the Queen enough to stick in an insult every chance he got. Now, "Her Royal Majesty" was definitely pissed; if that wasn't surprising enough, Sasuke had done anything to make the sudden mood swing occur.
So,
The former was decided on. His arms fell to either side of him, hands now unclenched. "Try it," A challenge, of course. They were still in the Cheshire Cat's forest, therefore there was no way in hell he could lose to any challenge that Itachi sent at him. Even if it was physical combat.