After their initial conversation, Draco was expecting a woman who was attractive enough to use her looks strategically, so he wasn't particularly surprised to see that she was young and pretty. The glasses perched on her nose were an interesting touch, however, as though she was playing at being a professor.
Hopefully that meant she would be taking this interview somewhat more seriously. He was in the mood to talk seriously about his future, not deal with random comments regarding her tits.
He gave her a polite smile, gaze still a bit calculating, and inclined his head ever so slightly. "Yes, Professor," he said. "May I come in?"
No need to be impolite. And he hoped it was implied from his choice of pronouns that he intended to come in alone.