Chocobos clearly took the place of horses and cattle in some worlds, he has theories about all of that, theories that Tidus is blessedly spared because Xehanort can and would go on and on about things nobody else cares about.

"I think, if you had the tech, it could LOOK like a ball on the outside, but the inside would be very different." It's enough to motivate him to pick up his pencil and notepad again, starting in on an absent doodle. "At first it might not be, you'd have to bring room things in there first like chairs or a bed or whatever, but I don't see why the interior shape should be dictated by the outside shape if it's a dimensional pocket. Right?"