"Flare" explores the way poetry relates to the world, while being, itself, a poem. Nifty, no? What can we say? It's a complicated relationship: a poem is not the things it refers to—it is not the world—and yet it has a sort of living spark and can teach us about the world. The speaker also muses on poetry's purpose. It can be a source of comfort, she tells us, and can help you feel "less yourself than part of everything." Bonus.
Although we might think that being reminded that we are reading a poem would take us out of the poem and make it less engaging, somehow the opposite is true here. By defining the poem in her strange way, and distinguishing it from the things it describes, our speaker in fact increases the sense of connection we feel between ourselves, the poem, and the world it describes.
The poem's most effective poetic moments are when it's describing the natural world using figurative language. When it's talking to us, we're mostly just annoyed.