action;
[ Riker gives it just a beat, then he moves to sit down on the bench, leaning forward so that he has to look up to her no matter what. It's deliberate from him; if she's going to pull a power move on him and make standing up dominance, then he's going to submit himself. Basic diplomacy. Staying up is just a good way to get the other person's back up.
Still, this is a very extreme reaction to a simple thing. Perhaps she's expecting more military a grilling from Riker than he intends. Maybe this really is just the pain of loss. ]
Politeness doesn't have to be a charade. As for your relationship with--with Jean Luc... I can't expect you to believe me, but I have no interest in making you feel uncomfortable, and an inquisition into all of that, particularly when the loss is still raw for both of us, would be indecent of me, let alone unfair.