。
She bought it at the butcher's.
Literal
She [topic-は] that [object-を] butcher [at-で] bought.
肉屋 ('butcher shop, butcher') is built with the productive suffix ~屋 ('shop selling X / X-seller'), which generates a long list of trade and shop names: 本屋 ('bookstore'), 八百屋 ('greengrocer'), パン屋 ('bakery'), 床屋 ('barber'), 魚屋 ('fishmonger'). The same suffix can also name the shopkeeper personally ('the butcher / the baker') without a separate word for the person. The で marks the location where the buying happens — 'at' the butcher's — distinct from に, which would mark a destination or stopping point.