His white and black wings flap once as he straightens up and turns toward the voice. A young man seems to be the owner of the voice. He looks vaguely familiar, but Aziraphale is fairly certain they hadn't spoken before. This world is too small not to at least recognize people, even if they hadn't properly met.

Finally his wings settle into place against his back and he smiles at the young man. "Hello. I'm sorry, I didn't mean to startle you, dear boy."