。
She skimmed through the magazine.
Literal
She [topic-は] magazine [target-に] roughly eyes-passed-through.
目を通す is a vivid Japanese idiom for skimming — literally 'pass one's eyes through.' The に on 雑誌 marks the destination of the eye-passing, the thing being skimmed. ざっと ('roughly, briefly, in broad strokes') intensifies the casualness of the skim. Standard verb phrase for any quick review of written material — emails, documents, magazines, contracts. The opposite full-attention reading would be じっくり読む ('read carefully, really sit with it').