Claude Monet’s The Magpie (Paris: Musée d’Orsay), painted in Étretat on the Channel coast near Le Havre in 1869, is universally acknowledged to be his early masterpiece. Robert Gordon and Andrew Forge call “the miraculous [Magpie] the prize of the joyful winter at Étretat.” Mary Matthews Gedo states that it is “one of the most magnificent snow scenes in his entire oeuvre.” And Alice Thomine-Berrada concludes that by “choosing a light palette and applying a delicate touch to the colored rendering of shadows . . . Monet created one of the first masterpieces of Impressionism.” But any analysis of Monet’s dazzling technique and subtle...