Their comeback has gathered a lot of attention, I think people have high expectations ever since Rock U, they probably wanted something more. While Pretty Girl is almost in the same genre as Rock U, it's a much better song as everyone agrees. This will be able to bring back quite a lot of old fans and new ones, too. It's a song that's easy to listen to, to sing to, it's catchy and cute. I guess they chose the right one this time ^^