He's left somewhat dumbfounded, but Tidus does recover, slowly. Takes what he can from Loki's theorising and translates it as something simpler in his mind ('Something somewhere can change the city') so he can at least return to the conversation. Somewhat.

"Mmm... I guess it is?" A rub to the back of his head. Recovery still in process. "I really don't get it," obviously, "but I mean... I figured this place was way ahead of anything I knew back home. Bringing us here, and everything."

Especially the everything part. Plenty vague, but something more to him.

"But you haven't ever looked at the new buildings, and it's kind of...seemed familiar to you? Does that make sense with what you were saying?"