From "How ‘Orwellian’ Became an All-Purpose Insult" by Jennifer Szalai (NYT).
The top-rated comment over there is: "To accuse the opposition of being Orwellian while actually being Orwellian has become the stock and trade of the right. How Orwellian."
Does it make sense to refer to a "biography" of a book? Well, first, it's in the book's subtitle, "The Ministry of Truth: The Biography of George Orwell's 1984." Second, "bio" means life, so we can understand the extended use of the term: It means that the book has a life. Third, I suspect the usage is explained in the book, and it's my blogging practice to buy the book in Kindle form so I can do a search when I have a question of this magnitude.
But, wait. I'm reading the OED definition of "biography": "A written account of the life of an individual, esp. a historical or public figure; (also) a brief profile of a person's life or work. Later more generally: a themed narrative history of a specific subject in any of various written, recorded, or visual media." An example of that more general use is the 1999 book title: " H2O: a biography of water." And there's an 1848 book title: "The plant; a biography."
So I don't have to buy the book, but I will. Such is my dedication to this blog. Here's the closest thing to an explanation for the use of the concept "biography" to refer to a book about a book:
There have been several biographies of George Orwell and some academic studies of his book’s intellectual context but never an attempt to merge the two streams into one narrative, while also exploring the book’s afterlife. I am interested in Orwell’s life primarily as a means to illuminate the experiences and ideas that nourished this very personal nightmare in which everything he prized was systematically destroyed: honesty, decency, fairness, memory, history, clarity, privacy, common sense, sanity, England, and love....