Nonfiction, including poetry that is basically nonfiction, doesn't have to be just about what happened, or what we saw. It can also be about what we thought we saw or what we wished had happened. Robert Frost's "Looking for a Sunset Bird in Winter" explores and expands a brief moment when the narrator thinks he sees a bird. The imagery helps us get a sense of why he might yearn for a bird. What else might he be yearning for?