As he's looking over the rock, which looks him over right back, he hears a small chuckle, along a waft of smoke on the air. The smoke itself is tobacco, but mixed with something sweet, almost cinnamon, maybe?

If he looks up, Yuuko is observing him as he in turn observes the rock. In answer to his unasked question she says "It's a pet. I think it's terribly cute" She remains enthroned on the overstuffed chair she'd picked out for herself, and props her chin on her hand as she looks at him, her small, enigmatic smile unwavering.