Teacher

In the chapter titled "Retarded", Carol draws a portrait of the Duke of Alva. The last time the class took part in a drawing activity, Carol drew a man hanging, an clear sign of WWII (or just war and death in general). However, the teacher was less that pleased with the illustration and Carol merely received a "that's nice." On the other hand, her classmate drew a picture of "two fairies on a toadstool" (5) and was rewarded with wonderful praise from the teacher. In a jealous rage, Carol scribbles all over her drawing and sketches "five [fairies] in the snow and on on top of the watchtower" (5) instead. Now, as she draws the Duke, she tries "to please the teacher" (95). The man has "cruel lips and a bloodthirsty look." (95) The one thing the teacher notices however is the "little black square under his nose" (95). The moment I read this line, I knew that it was Adolf Hitler's infamous moustache. Instead of realizing this allusion, the teacher "exclaims, 'What a wonderful moustache he has!'" Between the hanging prisoner to the Adolf Hitler moustache, the teacher never notices the war emblems in Carol's drawings. Although we have discussed this in class, I still wonder: is the teacher unable to catch these insignias because she doesn't know enough about the Holocaust, or is she "not noticing" them on purpose? There doesn't seem to be enough context to answer this question accurately; nevertheless, it is still a topic that confuses me and if anyone has any ideas, please feel free to comment.