In Nude (Study), Sad Young Man on a Train his transitory though acute interest in Cubism is manifested in the subdued palette, emphasis on the flat surface of the picture plane, and in the subordination of representational fidelity to the demands of the abstract composition.» (marcelduchamp.net)
When you look at it, the flat surface of the picture seems to heave and ripple before your eyes. (bloomberg.com)
Like Halvorson's earlier works, these are also poised on the boundary between illusionistic, depicted space and the material surface of the picture plane. (brooklynrail.org)