Sunlight Study at Chantilly Johan Georg Arsenius (1818-1903)

The picture has something of this: mammal, cavalry, seated, horse, herder, camel, herd, equestrian, livestock, cowman, group, people, farm, transportation system, gallop, saddle, rider, animal, motion, mare.
Perhaps it’s a painting of a group of men on horses and a picture of a man on a horse on the other side of a painting.