One of the many Americans who worked at Giverny during these years, he became a familiar of Frederick Frieseke and together they often met at Monet's home to paint, critique, and socialize. Miller readily adopted an aesthetic similar to that of Frieseke: wistful maidens relaxing in sun-flecked gardens painted with broken strokes in impressionist colors. Repeated diagonals of figures and furniture generally characterize the patterning of his canvases, a dynamic that strengthens their inherent introspection.

When he came back to the States he taught for a while in Pasadena, California, strongly influencing the impressionist movement just emerging there. After the war he purchased a home in Provincetown, Massachusetts, where he remained until his death in 1943. It was his avowed intent to please with his canvases, painting them, he said, "not for the staid environment of museums, but for the comfortable intimacy of people's homes." "Art's mission," he asserted, "is not literary, the telling of a story, but decorative, the conveying of a pleasant optical sensation." Though they have been dismissed as "confections," his works have continued to provide modest pleasure.