。
She bought this pen at that shop.
Literal
She [topic-は] that shop [at-で] this pen [object-を] bought.
A clean demonstrative-pair example: その (that, near listener / previously mentioned) on 店 and この (this, near speaker) on ペン — the contrast highlights the speaker's perspective on each. ペン is a long-domesticated English loanword that has fully replaced any native equivalent for the modern writing implement. で marks the location where the buying happened. The simple structure makes this a useful learner reference for how Japanese carves up demonstratives by spatial-or-conversational distance.