sentences:  His work has been featured in exhibitions in Europe and the United States, and he was commissioned by the White House in 1959 to paint a portrait of U.S. President Dwight Eisenhower.Pissarro's work has evolved through a variety of different styles and techniques, from abstract to avant-garde.In 1989, he began a series of contemporary landscapes which were signed "Isaac Pomié" in order to distinguish them from his traditional works.