I think

it is a bookshop that sells hats, rather than a hat shop which .... 
Many more books out of shot. The cheerful lady spends other weeks invigilating A-level Art exams, the school I was visiting this morning to talk about IT stuff. The Mad Hatter Bookshop. 

And nearby is the excellent bakery tearoom - if you want Cotswold Charm, in the form of a serious all-day Breakfast, you could do worse.