The demon wouldn't be sure exactly what new, profound thing showing his eyes had revealed other than that Crowley was a serpent (or The Serpent for as much good it did him). After all, there were far more obvious tells about his demonic nature all out in the open; the scaly feet, the feathery wings, the entire Ramones discography on his phone...

"Mate. Mate. You're not a snake. Or an owl. Or a chesspiece. You're human. One-hundred-percent. I know this because I know what humans smell like."

Crowley was starting to suspect there were two very different conversations going on here. The demon was trying to scheme and maybe get this human to lay off the blatant reptile stereotypes, and he wanted to be... an owl? Of all things? Was he part of that furry subculture or something? (Would it be the feathery subculture in this case?). Should he ask? Oh shit, was it rude to ask if someone was part of a peculiar subculture?