Pretty sure the poster was referring to Kula's Angel themed outfit from SNK Heroines. The one with the cowboy boots that are too big and would just fall off of her if she tried to walk. It was the pic in the post the user was responding to.
Hey, you asked :p Really don't see the problem with her belt buckle honestly.
TBF I think the only one who's really shown age is MAYBE Terry (and Rock if we assume him in XIV as DLC is properly considered canon), everyone else is in that Pokemon Anime-like Time Freeze. Sakurai pokes fun at this in his Terry video. KoF/AoF/FF has some really cool lore but their interpretation of time is a mess.
And yeah, with Kyo I was talking about his normal form to his NESTS form, which does seem somewhat older, but by a few years at best. Iori's DLC look in XIII also looks slightly older, but it might just be the outfit.