Here’s one of my first test images:

Original is below:

Here are the steps from the video.

Basically, to create a more realistic photo, one would like to use the Lens Blur, but you can only apply a lens blur to a rasterized mask vs a Smart Object where you would create the gradient blur.  I’m guessing most people stop at the gradient blur, but this technique adds a finer quality to the finished product, stead of a hazy look to the image.