I always have an eye out for good teaching, in life and in films, and have always liked the way the professor is introduced, as well as his later encouraging Jo to write more realistic characters.
When Jo first meets the professor, there is the obvious, broad depiction of his making learning enjoyable for the kids -- the bear rug bit.
But, I like what happens after they are introduced, when he gets the kids to help put away the linens.
Those few seconds show his warm personality and instincts as a teacher -- he prevents the maid from dumping the whole stack on the oldest child, divvies up the work between the children and himself, jokingly gives them military ranks (a nice way to make sure the boy doesn't balk at doing domestic work), and marches them off singing "Marching Through Georgia."
I just noticed that, as they march off-screen, he parodies the lyrics by singing
"while we are marching to the linen closet!"
I never noticed that before.