Art is worth our attention when it takes a "subject" and makes it aesthetically compelling. At that point the subject becomes irrelevant.
Initially this put me in mind of Kundera who writes, in The Art of the Novel, that Kafka 'transformed the profoundly antipoetic material of highly bureaucratized society into the great poetry of the novel; he transformed the very ordinary story of a man who cannot obtain a promised job (which is actually the story of The Castle) into myth, into epic, into a kind of beauty never before seen.'
But Green has gone further than the possibility of a transformed 'subject' here - further than even Proust's description of his work as a sort of optical instrument for the reader to read within themselves. I am reminded of Deleuze using Malcolm Lowry's term, 'a sort of machine', in Proust and Signs, to analyse the mad, webby construction of the Search. I am reminded, too, of the writing of Thomas Bernhard - as well as his description, near the end of his memoir Gathering Evidence, of reading Dostoevsky's The Demons:
Never in my whole life have I read a more engrossing and elemental work, and at the time I had never read such a long one. It had the effect of a powerful drug, and for a time I was totally absorbed by it. For some time after my return home I refused to read another book, fearing that I might be plunged headlong into the deepest disappointment. For weeks I refused to read anything at all. The monstrous quality of The Demons had made me strong; it had shown me a path that I could follow and told me that I was on the right one, the one that led out.
The work as an optical instrument, a machine, a drug, a monstrous quality; the experience of reading the 'subject' itself.