Artist-illustrator Norman Rockwell's rosy America and literalist technique might polarize opinions, but there's no denying the permanence and influence of his vision. Norman Rockwell: Behind the Camera, a new book with a companion exhibition at the Norman Rockwell Museum, shows Rockwell's use of photographs in his illustrative process. NPR reveals this new side of Rockwell's story, as told by his reluctant photographer and a cast of models who posed for him.