One of Four Portraits of Horses James Seymour (1702-1752)

The picture has something of this: cavalry, horse, seated, mammal, people, equestrian, action energy, rider, competition, man, run, mare, wear, saddle, bridle, recreation, horseback.
Perhaps it’s a painting of a man riding on the back of a brown horse on a green field with a blue sky and white cloud filled sky in the background.