In volume 1, when Sakura sees flashes of images, those weren't memories. Those were predictions. You saw Japan, where Kurgoane would come from to join the group. You saw Celes, where Fai would come to join the group. You saw Fei Wong Reed's mark, which will play important in journeys in the future(future from volume 1, that is )
That capsule scene hasn't happened yet. And I think that's definitly our Sakura in that capsule. Now whether that Syaoran is the real or clone... who knows. But I can't help to think that real!Syaoran doesn't love our Sakura but another Sakura in different dimention. I mean we don't know where this Syaoran was before he got captured, right? Not to mention real!Syaoran himself says "The one that felt that Sakura isn't "my heart". It's yours!" in chapt. 122 to the clone. So it's the Clone who liked our Sakura, not the Real. But the fact that Real Syaoran calling our Sakura was "that Sakura" is what's making me think there might be another Sakura waiting for the Real Syaoran to return...