you are an archangel or one of hells dukes you can pick.

you are a spy and need to blend in with humans to not cause suspicion…One day, you come across aziraphales book shop! Finally you have found it!! So you walk in to be greeted!

Azira: “hello! Welcome to aziraphale & co! What is your name?”

sat next to him must be the “co.” As there is a guy sat weirdly on a chair..you can’t see his eyes through the sunglasses..but you get the feeling he is judging you..this must be Crowley.