I think Edwards actually has a completely different approach. The book referenced in the article uses the idea of making an object out of basic shapes: put together some squares and circles and you have an elephant. The only problem is that that approach only works for making a kind of stencil image of an elephant and totally fails for realistic drawing. Edwards' approach is totally focused on convincing the brain to drop its preconceptions (like the squares and circles) and transfer the reality of the actual lines and shadows that are in front of the eye to the paper. You actually have to stop the mind from trying to substitute it's template of an idealized "elephant" (or the idea that I should draw a circle because someone told me to draw a circle) and let the pencil just follow the eye.