Jaune does not notice the look, because he doesn't notice her right away. But since his whole point of slipping outside was to scope out and find people he does notice her upon a quick scan.

He even manages a rather comedic double take -- because he certainly wasn't expecting her. There's not much of a hesitation as his hand goes to the hilt of his sword, though given how uncertain this situation is he doesn't draw it -- not yet. He needs answers after all.

"You! What are you doing here?"