It's a small circular chamber wrapped in bookcases, invoking the round reading rooms of the nearby Radcliffe Camera and the old British Museum, and even the spiralling stacks of the new Seattle Central Library; or maybe, with a member of staff installed in the centre watching every direction, it's a mini Panopticon. Arrangement in a ring gives good metaphor - start anywhere, end nowhere - but (as j4 observed) is a suboptimal choice for storing cuboids.
The arrangement is unusual in other ways, as I had been warned. The classifications include 'INNOCENCE', 'RELATIONS' and 'INFORMED RANTS'. Fiction and non-fiction mingle promiscuously. In fact, deciding where to replace a book after removing it to show a fellow browser can be a problem (or an opportunity).
The selection reflects the collected weekend broadsheet book pages, for brows from middle to high. The display is egalitarian, each title displayed spine-on in a single copy. The stock is new and attractive: its closest concession to the little books-which-are-not-books which infest other bookshops are pocket Hesperus editions.
It lives on Turl Street, at the corner with Ship Street, which I specify because it's the first organization without a website I've come across in years. (There's a cafe, too, and apparently a private members' club.) Consider this an advertisement.