Critique a Balls Still Life

Each year I fall in love with a different group of students. I grow close to them by learning about them and why they create the art they make. I meet their family members and friends and watch them endure the drama of teenage life. This year I have three boys that check in with me each morning and again before they leave. They stand in front of my desk cracking jokes and giving me updates on the progression of their portfolios, social life, and school work. They are Hamsel, Michael and Alex.
They are all three very handsome and very funny and very creative in very different ways. Hamsel is animated when he tells a story and is usually the loudest voice in the room, but that's not why he always has the most attention. The kid has a really creative sense of humor and busts on people constantly but with a sensitivity that is in no way mean. Michael laughs along with him mostly, adding an occasional quiet comment that strengthens the jokes Hamsel creates. Alex is the articulate and intelligent jokester, you have to think about what he says before you laugh. They are constantly reciting lines from movies together as though they were the actors in the film. Without going to a theater I have seen trailers for "Superbad," "Knocked Up," and most recently "Semi Pro."
Hamsel and Michael are both in my AP Studio Art Class, they are with the best of the best. We hold bi-weekly critiques to help each other build strong portfolios to submit to College Board for college credit. At this time of the year we are working on our Concentration section; the students create twelve pieces that develop from one theme. During critique Hamsel and Michael are incredibly helpful to their peers as they offer up insightful suggestions and creative solutions that the others take seriously to heart.
A boy I call Vargas decided to do his Concentration on Sports related still life drawings.
This past week Vargas hung his very simple drawing of a football, a basketball and a baseball on the wall and fell victim to the creative humor of Hamsel and Michael. I began the comments by saying, "It's well drawn but is missing the contrast and value changes that make your work impressive. The balls themselves have no value changes in them yet there are very strong cast shadows under them."
Hamsel added, "Yea man, yea. The balls all have the same value." Just a snicker now but that's all he needed to fuel the fire.
"So what about dark balls vs. white balls? What if the balls are touching? And texture, you can't tell if the balls are rough or smooth. Maybe draw some balls bouncing." The laughter is loud and then settles so someone can add a real helpful hint, "hey, like...why don't you draw what a soccer ball looks like when it's being kicked. Like, it turns into an elliptical shape and foreshorten it so it looks like it's exploding off the page!"
Hamsel adds, "yea, EXPLODING BALLS!"
Michael chimes in, "Raining balls man, jus' all kindsa balls fallin' from the sky." Laughter is good, we need laughter so I do little to stop it but I do try, "you can make your Concentration turn toward something more like impact in sports. Make it more about Impact than, you know..."
Michael says quietly, "softballs."