The poem is about an unnamed woman. She's really quite striking, and the speaker compares her to lots of beautiful, but dark, things, like "night" and "starry skies." The second stanza continues to use the contrast between light and dark, day and night, to describe her beauty. We also learn that her face is really "pure" and "sweet." The third stanza wraps it all up – she's not just beautiful, she's "good" and "innocent," to boot.