Complex sentence: It can be achieved using an image editor like Photoshop by blurring the top and bottom of the photograph so that only the subject is in focus, for example by using a gradient map focused in a middle stripe, and lens blur filter having applied.
Split into simpler sentences: It can be achieved digitally by blurring the top and bottom of the photograph so that only the subject is in focus. It needs a gradient map focused in a middle stripe, and lens blur filter having applied.