Her photoessays have appeared in Life, Look and the London Sunday Times, among other journals. She established her career with sensitive essays in Life and Look on such subjects as childbirth, small-town America, Joan Crawford, and Clark Gable. Currently she is based in Europe and New York.
Arnold made a film in Arabia, Behind the Veil.
Her widely varied photographic subjects have included mental institutions, prisons for delinquent boys, divorce courts, little-known aspects of Russian life, the Queen of England, migratory potato pickers on Long Island, the Archbishop of Canterbury and Rudolf Nureyev.
She is a member of Magnum.