???
He could tell he wasn't human at first glance?
That statement sounds kind of weird, doesn't it? Like it's slinging an insult at him... But on further thought, it's not insulting because he literally isn't human; he is a dragon, a pureblood Golden Giant Dragon.
So the Human Viscount means that the first time he saw him, he saw through his disguise and knew he wasn't human but a Golden Giant Dragon?
Are this guy's eyes that sharp?
Can he really see past appearances and glimpse his true form?
He has the art of dragon recognition.
What does that last remark mean?
The Human Viscount asked him, "Do I look human to you?"
Isn't he human?
No matter how you look at it... he's human, an exceedingly fine specimen of humanity.