He is haunted by a demon, a demon against which he feels powerless, because in its first manifestation it has no face, no name, nothing; and the words, the poem he makes, are a kind of exorcism of this demon.
If you use Facebook - as I do - Facebook in all likelihood has a unique digital file of your face, one that can be as accurate as a fingerprint and that can be used to identify you in a photo of a large crowd.