“She Walks in Beauty” isn’t set in a concrete time and place, which means that the setting is open to interpretation. On the one hand, the speaker could be in the midst of observing a woman who’s walking. If that’s the case, then it’s possible that the poem could be taking place during some evening or nighttime social occasion. Such an interpretation would help explain why the speaker begins the poem by comparing the woman’s beauty to a cloudless night sky. Perhaps he sees her face subtly illuminated by a torch or streetlamp against the night sky, and this contrast leads him to his opening simile. That said, the speaker’s reference to the night sky doesn’t necessarily indicate that the poem takes place at night. In fact, it’s entirely possible that the speaker isn’t currently observing anyone, but rather recalling a memory of woman he observed on a previous occasion. If this is the case, then it makes more sense to think of the poem as taking place entirely in the speaker’s mind. That is, it takes place a realm of philosophical abstractions about beauty, virtue, and their relation to one another.