Norman Rockwell made this painting, sometime during his career, using oil. The way he worked—the thin, washy paint and tight rendering—that's his whole deal. It’s all about the image, about storytelling. Look at how he renders the kids’ faces, all scrunched up in concentration. He really captures the seriousness of the game, you know? It's so precise, like you could reach out and touch them. And the marbles! All those little glass spheres, each one catching the light just so. It's meticulous, the way he’s recorded everything, but at the same time, it feels so alive and in the moment. The composition, too, forces us to look down, just like the other children, as if we are watching the scene from their point of view. It reminds me a little of someone like Fairfield Porter, maybe, in that they both are documenting these intimate scenes of everyday life. Rockwell does it with that hyper-realistic illustrative style, while Porter is more loose and painterly. In the end both styles offer a kind of window into another world.