Riding in the Bois de Boulogne (also known as Madame Henriette Darras or The Ride) Pierre-Auguste Renoir (1841-1919)

The picture has something of this: cavalry, seated, mammal, people, equestrian, wear, man, two, horse, competition, military, weapon, gun, recreation, rider, soldier, motion, uniform.
Perhaps it’s a painting of a woman riding on the back of a white horse next to another woman.