Graham developed a style that combined classical drafting with surrealist and occult symbols. He often used a grid system to organise his compositions. His later portraits, including Madame Sijou, frequently feature subjects with crossed eyes. He believed this physical trait indicated a connection to a spiritual or subconscious realm. His work moved away from pure abstraction toward a highly personal form of figurative mysticism.

Collectors value Graham for his technical precision and his strange, psychological subject matter. His drawings and paintings possess a quiet intensity that fits well in contemporary interiors. The works offer a sense of historical weight without being traditional. Pieces like Equestrian and Portrait of a Man with Suspenders provide a sophisticated alternative to more common modernist prints.