。
Look carefully at the map on the wall.
Literal
Wall's map [object-を] carefully look [polite imperative-なさい].
注意して is the て-form of 注意する ('to pay attention'), here functioning adverbially as 'carefully/with attention.' 壁の地図 is 'the map on the wall.' The ~なさい imperative makes the whole thing a polite-but-firm instruction, characteristic of teacher-to-student speech. 注意して + verb is a productive way to mark careful action.