If you are working on a real design, I can help you troubleshoot specific steps: Are your chains not closing?
Are your finish passes taking too long?
He selected a 3D Roughing toolpath with a 1/4" ball nose end mill. This would strip away the bulk of the wood, leaving a "stair-step" version of his art. Mastercam X2 Art Tutorial
He navigated to the Art Texture library. He selected a "cellular" pattern, scaling it down until it mimicked the layered look of flight feathers. If you are working on a real design,