Many of the people didn’t like this. Facebook is not looking that good with this update. Many users like this but most of them don’t. Maybe later, Facebook will revert back this update or improve this.
To revert back that black pop up pictures on Facebook, just open up a picture, when it pops up in the black windows, just press F5 on your keyboard and it will revert back to old layout. But you will have to do this for every picture. I’m sure there will be hack available soon that will permanently disable this. I will post that as soon as I get.