But in the context of T-ara, it isn't aesthetic weakness. Which means it's not weakness period — though it might turn out to be, if she doesn't continue to use it as well as it's used so far in T-ara; Hyomin is not yet a master of the high-pitched quaver in the way that e.g. Taylor Swift is. (Okay, competing meanings of "weakness": (1) not aesthetically effective, (2) not loud. The songs and arrangements are making her aesthetically effective, and for all I know she herself is doing so as well, since I don't know who chooses or decides what when it comes to the details of the actual sound. But anyway, she's not as loud and steady as many other singers, and given her role in T-ara, this sort of "weakness" is an advantage.)
Re: UPDATE
But in the context of T-ara, it isn't aesthetic weakness. Which means it's not weakness period — though it might turn out to be, if she doesn't continue to use it as well as it's used so far in T-ara; Hyomin is not yet a master of the high-pitched quaver in the way that e.g. Taylor Swift is. (Okay, competing meanings of "weakness": (1) not aesthetically effective, (2) not loud. The songs and arrangements are making her aesthetically effective, and for all I know she herself is doing so as well, since I don't know who chooses or decides what when it comes to the details of the actual sound. But anyway, she's not as loud and steady as many other singers, and given her role in T-ara, this sort of "weakness" is an advantage.)