Trowa finishes typing his current sentence before he looks over, but his face warms almost imperceptibly. (This is Trowa's version of a reply.)

He taps the button to minimize everything as he glances back at Quatre in return greeting, and fails to move away.

It's not that he minds Quatre seeing anything he's working on. It's not particularly Quatre's business, of course, but there's not a lot he'd keep secret from him, and he wouldn't work on any such thing in front of him anyway. But this isn't time-sensitive, and so there's no reason to make Quatre work to be properly courteous.