You may look at this picture and see something else. Like eggplants! But to me the first comparison was that this was a teacher holding forth on a subject of great interest . . . to her at least. There's one eager beaver student at the front, hanging on the teacher's every word. There's the one at the back, no doubt failing the course, who is looking at the ceiling in boredom. A couple look mystified as to details of quantum mechanics or onomatopoeia and the tall one is angry at missing the first few minutes of recess while the instruction drags on.
But, what about this one:
Definitely hanging on my every word.