Mr Wrenn, a horse breeder from Pickering, North Yorkshire, is depicted in a half-length portrait, facing slightly to the left of the viewer. He wears a grey coat with a dark collar, a cream waistcoat, a high-collared white shirt, and a white cravat tied in a bow. His powdered hair is short at the front and longer at the back, framing a pale face with blue eyes and a composed expression. The portrait is typical of the Georgian period, with its subdued tones that highlight the subject's likeness and his genteel social standing.