The difference is difficult to describe except perhaps by the aid of a musical notation. It is like the difference between two voices, and in spite of the highly characteristic matter1 of the lines, the reader feels that not Shelley but some other poet is speaking. What Shelley is doing becomes unmistakable in the third and last stanza. The corresponding lines, again in clear contrast with the lines surrounding them, have the same strange modulation:

So fleet, so faint, so fair, The Powers of Earth and Air

Fled from the folding-star of Bethlehem. Apollo, Pan and Love, And even Olympian Jove,

Grew weak, for killing Truth had glared on them.