i think this is finally some proof that Red-Haired-Girl is meant to be Kairi. If you look closely at the bottom pic, you see it's Kairi's original (KH1) outfit. they probably hadn't decided what Kairi should look like or what she'd be wearing in KH2 when they made the bottom image art, so they used her original look!
I'm guessing the bottom pic is a conceptual-art pic which was translated into game graphics for the top image much later. I've heard too many people say that Red-Haired-Girl is not Kairi...i refuse to believe it! =b
also, in reference to what some of you were saying about houses on Destiny Islands--This might be a bit of a stretch, but if you talk to Wakka several times (I believe it's on the first day on Destiny Islands? may be the second), he makes a comment like "Man, I'm hungry. Let's go home and get something to eat, ya?" Tidus also says "This island is paradise, with no adults to order us around." Yet we hear Sora's mom, and we also see when Sora looks out his window that the island is very far away. Some of you were commenting that maybe Destiny Islands has houses on it now--I think that Sora and his friends live with their families on a nearby island, and go to Destiny Islands during the day (further proof: "Riku's boat...and Kairi's!" references that they had to travel to the Islands by boat).
I dunno...what do you all think?