EASTHAMPTON – Tiffany Chappel of Amherst rubs pastels on paper. The shades of blue melt together to create an effect like the Monet painting beside her. Justin Kim, her art instructor, compares the two pictures. “Look, it’s almost exact,” Kim observes. “Yeah, it’s OK,” Chappel answers, modestly. Nearby, as Beatles music plays, Edie Oyola of...