You're not wrong, but it was from memory. I invite you to look it up and post the correct version.
I was the shadow of the waxwing slain
By the false azure in the windowpane;
I was the smudge of ashen fluff—and I
Lived on, flew on, in the reflected sky.
I think I did alright for recalling it from several years ago. I will in fact, retract my agreement and classify your criticism as overly harsh.