Sketch is angry at Donna. by @sketchtucker (Larry McKee)

One of Sketch's biggest pet peeves results from his desire for privacy. He likes to spend some time to himself doing whatever he feels like doing. His only request is that people knock before coming in; people "breaking in" tend to break his solitude bubble harshly, and that makes him furious. In this pic Donna had done so exactly, and Sketch is not at all happy with her. Donna seems a tad surprised as well as scared.