His discussion of the fourth ‘office’ appears in “The Language of Poetry ‘Dramatistically’ Considered.” Here he tells us, “We refer to the utterance as ‘portraiture,’ as the ‘self-expression’ of an agent, as an act characteristic of the poet’s ‘personality’ whether or not he so wills it” (ETSM 41). He seems to be suggesting that the text reveals something about the agent responsible for its production, particularly within a given scene, for he goes on to write: “[H]ere would seem to be the situation, as regards the ‘portraiture’ (be it voluntary or involuntary) in a work of art:

“Human personality is not just ‘pure.’ It is formed with reference to social roles. Accordingly, the ‘personality’ in a work of art impinges upon the social situation in general. Intrinsic analysis leads us to study the work of art as a kind of act in and for itself. But a concern with the ‘personality’ of a work involves us in the study of the work as the act of an agent in a scene” (ETaSoM 43).

I keep thinking in terms of establishing ethos within a text, of trying to build up a rapport with the audience by showing them that you have something in common with them. If you can show that your ‘personality’ is such that you are a reliable, trustworthy person, you can get them to listen. So within the text we drop hints as to our character to make those connections with our audience. That’s striving toward identification. But whether we intend to or not, we are placing information within the text that shows our personalities as agents situated within a given context (scene) and performing a certain act (composing the text).