In the Lilith's Brood trilogy, "Imago" is the first time we get a first person narration. It's the voice of an ooloi, and therefore one of the most foreign to us in the world of the book. This functions on several different levels. It serves the utilitarian function of decreasing the number of "it"s in the text, making syntax more understandable overall. But it also sets up a very interesting self-and-other construct, removing it from the societal and making it far more individual.