Upon hearing Claudius' voice, the little brown rabbit sits back on its hind legs, balancing on Lan Wangji's knee to peer at him. Meanwhile, Lan Wangji turns the white rabbit in his hands so that it can see Claudius as well and not be startled by the sound of another human.

As for Lan Wangji himself, he is so obviously happy to see Claudius that an actual smile would be unnecessarily excessive. "Claudius. Sit."