Lady and Gentleman on Horseback by Aelbert Cuyp https://www.nga.gov/artworks/1152-lady-and-gentleman-horseback
This large double portrait on horseback is unusual in Dutch art, because equestrian likenesses were initially reserved for sitting monarchs. Traditional portrait convention would have placed the woman to the left and slightly behind the man, yet this elegant lady on her magnificent steed occupies center stage.
Philadelphia, 1913: unpaginated, repro. 1914 Sedelmeyer, Charles.