Every celebrity has the image & each style of dress and Similarly, Taylor Swift faithful to her good girl image. Ordinary sang ballad songs, Taylor Swift synonymous with classic style and vintage clothing. It is also the choice when attend the BBC Radio 1 Teen Awards.
Wearing a white vintage dress, Swift look beautiful and simple style, although it looks simple but the back of the dress is open and displays a smooth back.
Ex-lover John Mayer is also wearing a pair of earrings that give the impression of lady look. 
Not just a guest, singer 22 years has also performed on stage. But unlike the red carpet, Swift appears more casual this time wearing a black transparent shirt and high wasted shorts, quoted by Dailymail.
Source:
http://etcfashionblog.com/wear-white-dress-taylor-swift-perform-wearing-a-white-vintage-dress.html