Three short lines, and a single image carries the whole thing: the speaker has just had their hair cut short and feels transformed. Without the weight of long hair, the head becomes a "globe," a bare, round shape. The surprising part is what comes next. Night "cannot endure" there, as if the exposed head were a small world always lit by the sun, with no room for darkness to settle.
The speaker seems to feel freed, even a little triumphant. Hair is often linked with shadow, shelter, or hiding, so losing it reads as a kind of opening up. Judging by the imagery, the speaker feels clear-headed and bright, as though something heavy or murky has been cut away along with the hair.
The mood is quiet, fresh, and a little playful. The poem is tiny, and that suits its subject: nothing extra is left, just a clean shape and a feeling of light. The title, "Shorn," adds a slightly stark edge, but the poem lands on relief rather than loss.