Art is all over the place in "To Helen." The first stanza contains a complicated allusion to the Roman poet Catullus, another one to a famous woman from Greek mythology and literature (Helen), and, possibly, yet another one to the famous Greek hero Odysseus (a.k.a. Ulysses). In the last stanza the speaker compares Helen to a statue, and he even mentions an agate lamp, which sure sounds like a work of art to us. The poem is about love, but it's also about art, and about how we use art as a way of thinking about, and describing, our world.
It is dangerous to compare people to works of art for it can make them seem less human. At times, Helen seems unreal—plastic, y'all.
"To Helen" shows how people often use art in order to understand the world around them. Thanks, art!