Weave is a hollow vessel; empty in its natural state, but able to be filled with a variety of things.
In this case, he is a shell for the energies of the dreaming world -- a collection of lands drawn from the subconscious imaginations of bedtime-travellers, all quilted into a delicate spiderweb-nexus of shimmering, glimmering, fine as spun-sugar energy. He is awash with an aura of gossamer glory, being channelled into every fiber of his body - as his claws continue click-clicking together in his constant, endless knitting.
He is without sense and without feeling, only existing to build his tapestry of fancy and whimsy.