John Hutchinson, critic and director of the Douglas Hyde Gallery wrote in the Sunday Independent that Henderson's paintings, "'demonstrate the fruitfulness of the no man's land between abstraction and representation", and "His images deliberately evoke the picturesque and romantic landscape conventions that originated in the late 18th century.....as well as the expressionist subjectivity of painters such as Jack B Yeats". Due to Henderson's disinterest in the commercialisation of his work he is sometimes referred to as Ireland's Invisible Genius.
