LotR -- Book 3 - Chapter 07 - Helm's Deep

[The Saucepan Man]

Originally Posted by Fordim

Inside the story, there is no metaphor around or about the blade’s glow: it really is glowing. But when we read it, in a world where there are no glowing swords, the only way to bring it into our own experience is to make it into a metaphor for something.

So those shadows that stretched to the walls weren't metaphorical - inside the story they really were wings.