In the second stanza he says "art thou" dat is he directly addresses the moon. These words make it clear that the poet is offering an idea descript of the moon in the traditoin of medieval love poetry. And he says that the moon is "pale for weariness" dat is because the moon is tiered of serching a companion for herself. And then the moon climbes the heaven and watches the earth.This means that the moon is now high up in the sky, because the sun has fully set by now and the dark hours have started. He says the moon is lonley among the stars because they have a different birth and so she remains lonely and keeps on changing lyk a joyless eye. Her eyes are joyless because she has no companion and she changes because a moon has its different phase. And we see the moon sometimes partly sometimes full and so on. And in the last line the poet say " that finds no object worth its constancy" i.e the moon realises that no one truly deserves her love and so she remains alone comapionless for ever in her own heavenly world wrapped with sorrow