I'm not sure that he does look angry. Physiognomy and physiology are not the Tapestry's strong points, so it would be very difficult to reach any kind of serious conclusion about what might or might not be being said in any scene. Is Harold hunched over because he's being admonished? Is Harold hunched because he is showing respect to his King? Is he hunched because the figure hasn't been executed very well in the Tapestry? There isn't enough real evidence in the Tapestry to reach a conclusive view.