The key here is the relative size of each figure. The relationship between the two is conveyed by the hand gesture of the tutor.
I was at the next table, but the two gentlemen were engrossed in figuring out economic elasticity (whatever that means).
They were talking about math. The teacher’s gestures were relaxed. The position of her right arm shifted, as she spoke to her student. I rendered it in each position, with lines that enclosed space. The student was trying to absorb the material. The student’s gestures were not exactly relaxed, but they were not hyper either. […]