You can't even read two lines without "Easter Wings" transforming before your very eyes, dropping syllables right and left as it shapes itself into a pair of wings. Even on a smaller scale, Herbert matches the stanza's transformation with the theme of transformation. As Adam falls from comfort to poverty and the speaker goes from sad to saddest, the lines follow the same pattern, contracting into two syllables. And when the speaker looks forward to rising out of this mess, the lines expand just as joyously as his hope. Herbert's bird imagery, expressed through similes and metaphor, gives the idea of transformation an extra, feathered dimension.
The changing shape of each stanza mirrors the transformation of the speaker, plain and simple.
Using the language of flight, Herbert compares the speaker's religious transformation to the soaring of a bird.