’Elis’ at Doncaster, Ridden by John Day, with his Van in the Background Abraham Cooper (1787-1868)

The picture has something of this: cavalry, horse, mammal, seated, competition, equestrian, action energy, mare, motion, rider, people, two, equine, jockey, racehorse, race, hurry, run, man, stallion.
Perhaps it’s a painting of a man riding on the back of a brown horse next to a man standing.