It is just two things: spirals and echoing. It comes out very fluid.
Come back out of that spiral until you almost run into the first one.
Now echo around the first one down to its base. Then echo back up around the whole operation.
Do one more echo around again and start the design again.
I think to do good freehand free motion quilting you have to have a certain amount of flexibility. So occasionally you'll only echo once, or just use one spiral in a tight space, or make some other adjustment to get it to all work out. So don't forget that if you try this pattern, you are authorized to change it on the fly as needed.
As with any new free-motion design, figure it out with pen and paper before you try stitching it!
P.S. You can see me stitching this design in my Secrets of Free-Motion Quilting class on Craftsy!