That video isn't the best example since Aislinn isn't smug at all, but it's the first thing I could find. If you can recall anyone in anime saying "ah, sou. hmmm..." in a blatantly disinterested/unimpressed voice, that's what it's supposed to be here, I think.
It's the kind of "heh" you make when you're absolutely desperate but still playing hard to get so you don't look absolutely desperate, but then your bluff gets called and you try to play it off as a joke while choking back tears of loneliness and despair.
That kind of "heh".
I see. Sorry ashi garashi, you should just lower your standards
