The HD remake of Final Fantasy X and X-2 came on one disk with a game select menu that pops up when you launch the disk. This menu had 4 options on it instead of the 2 I expected, so when I first started playing I had to check out what was going on. It turned out the other 2 were extra cutscene videos and I declined to read much after that. I knew I wasn't going to want to pick Eternal Calm until I'd finished off FFX and that was good enough for me at the time. But now I have finished FFX and it's time to watch the extra video that comes between FFX and FFX-2.
I did some more reading and I thought this video was made to help explain the story between FFX and FFX-2 but it sounds like it was actually just bonus content they made to include in the FFX International edition. And it was the enthusiastic response to the video that caused them to make FFX-2, not the other way around. I find that to be pretty interesting.
Anyway, the video takes place 2 years after the end of FFX and is trying to show what life is like for the characters in your party now that they're no longer on a grand adventure to save the world. This is something I've always wondered about for games like this... At the end of FFX Rikku and Yuna were, for all intents and purposes, gods. With the way the numbers shake out I wouldn't be surprised if Rikku could kill everyone in the world without fear for her own safety. Especially if you let her cast spells! (I mused about the ending of FFII, actually, and how the 4th character in that game tried to conquer the world in the middle and then at the end he just wanders off to do his own thing and no one seems to care. By that point he really was strong enough to conquer the world!)
What would super powerful people do in a world where they don't need to fight evil? Well, in FFX, it would seem that Kimahri becomes a father figure and teacher for his race. Most of the adult Ronso were killed off by Seymour because he's a big jerk. That makes sense. Kimahri is a nice guy and trying to get what's left of his people back on their feet seems like a great thing to do. Wakka and Lulu settle down and make babies. I can see how that would happen too. Rikku goes off adventuring trying to find long lost machina and teach people to use them. This is basically the same thing she was doing at the start of FFX and I'd imagine all those levels I ground up for her can only help with that plan. Auron isn't even mentioned, presumably he stayed dead this time. Tidus is alluded to, but also isn't really mentioned. That leaves Yuna who is the focus of the video. While the rest of the party was there to help out it really was Yuna that saved the world and the people treat her as such. Everyone wants her to join their teams and solve their problems and listen to them whine. Yuna seems to be bored out of her mind and spends all her time trying to drown herself. (Ok, not really, but she's trying to increase how long she can hold her breath underwater. Turns out Blitzball players are just really good at holding their breath.)
Rikku shows up in the video with a sphere that has someone who sounds a lot like Tidus trapped in a jail cell. This makes Yuna want to go on an adventure to find out what's going on in the sphere. Wakka thinks that's crazy and wants her to keep at her boring life. So as soon as Wakka wanders off (to talk to Lulu) Yuna says screw it and leaves with Rikku to go on an adventure. Before they go Rikku muses about how Yuna's too much of a celebrity and they're going to need a disguise for her...
Which is apparently why Final Fantasy X-2 exists at all, and has the garment grid. Because people wanted to know more about this adventure Yuna was going on with Rikku and because Yuna was going to need a disguise.