I think it might be the fact that Claire is so skinny that also makes her look rather tall.
Her limbs are thin and give the appearance of being exceptionally long for her size.
But that's not what makes these legs interesting... it's the fact that she holds them straight in the air.
You try holding your legs straight in the air while sipping some Gatorade or a beverage of your choice.
Guaranteed you'll have some pretty nice abs in no time.