After viewing the picture, I would describe the painting as Impressionistic.
You can eliminate surrealism insofar as that movement, if I recall correctly, was founded by Andre Breton around 1924 when he published the Surrealistic Manifesto (which I labored with <groan>, back in college). By then, Waterhouse had already been dead.
"In general, realists render everyday characters, situations, dilemmas, and objects, all in a "true-to-life" manner. Realists tend to discard theatrical drama, lofty subjects and classical forms of art in favor of commonplace themes."
After viewing his portfolio, one pretty much dismisses Waterhouse as a Realist.