It is more conducive to learning new patterns when you remove the the postural work of standing. While lying down, we can do movements we cannot do while upright, due to the decrease of the anti-gravity muscles. You want to eliminate the need to balance upright while paying attention to movement because it increases so much proprioception.
In other words, you will do yourself more of a favor by doing a lesson on the floor, then getting up to see how it feels.