That question, too, merits a longer look. Ambiguous at first, eventually it ends with a particular expression of his: an all-over implication of a smile, without any smile taking place, made possible by the incredibly subtle finesse in the muscles of the human face.
Its exact meaning may still be difficult to discern, but that's hardly his problem.

"I've only recently begun to explore that. There's little emphasis on expressive culture in the Circle, you see. Maker forbid we develop any strong interest in the wider world." He's watching a tree as he says this. "But I've always been fond of exploration, or... a sense of mystery. An image that leaves you wondering."

Lest this get too deep too quickly, "Of course, sometimes it's nice just to see a lovely picture of an apple, or something. In the right hands, under the right eye, anything can become beautiful."