That was the thing about Jack's class and personality. He brought such enthusiasm for the medium of illustration, that he swept up the class in the drama of each model setup and invited us to delve into our imagination to make the "story" presented that much richer. For a first year undergrad class, this was a big departure from just learning the "basics" of illustration.
The blog above details more of Potter's Principles than my quick sketch above. I quickly tried to jot down the things I remembered from his class and put that into my sketch. It was a great time for continual learning and inspiration.