"Irrelevant." A token Borg answer, of course. But he does seem genuinely curious as to why his knowledge of Picard is not on equal scale with her own knowledge of him. Facts. Moments. That is what makes up the life of every civilization the Borg had ever conquered.
Thusfar, he looks nonplussed with her goading him. Merely emoting a detached curiosity. "Humanity. Is inferior." It's said simply. But the unasked question is why he would want to understand an inferior race.