Songstress IU has endorsed clothing brand y'sb through several seasons.  After causing a stir with teaser photos, y'sb unveiled official prints of  their 2011 F/W Collection creating even more buzz.  As a treat for fans, a special behind-the scenes video was also recently released. IU has been making headlines for her new more-mature look. She does a wonderful job showcasing the stylish, yet still comfortable clothing.As evidenced in the BTS video, IU seems to have become more comfortable with the camera.  She is able to switch from cute and adorable to wordly in the same photoshoot. Watch her various transformations and the final Official photos below! [gallery] Do you like this more polished IU or do you missed her more child-like charms? Source for images: Newsis