Short Answer: comic Relief You have to read around this speech a little bit. Mephistopheles (a demon pretty high up in "the organization") comes in and Faustus makes the comment after all his incantations (which is above your quotation) that he (Meph) is really ugly and is better suited being an old Franciscan Friar -- not a thing you would expect a devil to be.
It's wit and an audience member would smile wryly at the comment. It is not belly shaking laughter. It is just wit, sharp and pointed. (Sort of like the devil himself).
Answer: Comic Relief
One other comment. Try fitting any other answer into those two lines. None of them will work.
