August 15, 2012 03:56 AM EDT
In the uploaded photo, Yoona and Yesung is smiling and looking at the camera. Also, they are wearing same black glasses like couples.
The pale skin and facial structures that are similar attracted the attention of internet users.
The internet users responded to the photo saying "I feel good looking at their photo," "I wish they would go out," and "They look like couple or siblings."
Photo Credit: Yesung Twitter