The Wonder Girls attended the the Chloe fashion show in Shanghai, China. They were there to help promote the French fashion label Chloe, to the people of China. The fashion show was also streamed live online. This event marked the first time China has had a digital fashion show. This works well with the increase of popularity in internet shopping.
source: hellokpop, followWG, WG's soompi thread 1, 2, 3