As Picasso’s “Les Demoiselles d’Avignon” turns 100, Thomas Hoving confesses his own ambivalence about it and muses that the painting “is a deliberate throw of the gauntlet, a ‘screw you’ to the entire history of art. … Every aspect of the painting is at war with every preceding work of art. A more complete denunciation of accepted humanity, accepted beauty and every artistic style that preceded the work cannot be imagined.”