Look at these MVs! (If you have time)
And like many many more. I'd just like to say that I think it's naive to for them to believe that they're only worthy of love if they look pretty. In fact, I'm apprehensive about looking pretty and hence attractive. I feel that external appearances are superficial and relationships built mainly on them aren't likely to be sustainable.
Of course, that doesn't mean that I don't believe in putting effort into appearance. I think a lot of people judge by appearance, and how well you look reflects, to many, how professional you are and how good your judgement is (at least aesthetically), especially in the working world. I think looking appropriate is also a sign of respect to the people you're around and for the event you're attending. In addition, how you choose to look is also a reflection of your personality. For these reasons, I will pay more attention to how I look.
BUT I think it is pointless to believe your worth is determined by how good-looking you are! There are so many reasons for not looking good - what you're born with, whether you choose to spend your time and money on more worthy causes, not wanting others to feel you're superior to them etc. Just because you're not looking good doesn't mean the person you are underneath is the same. The kind of kickass spirit shown in the the first MV 'I will show you' doesn't need to be pulled off by good looks, flashy short dresses and flying hair. Those are just distracting implements that people expect to be there. They don't need to be. It's the underlying sense of self-respect that's important.