To make this trompe l'oiel carving 'work', you need to be acutely observant.
That's where our model comes in: Look really closely. Describe what you see, the hills and valleys, the form and space; how parts connect and run into each other. Talk to yourself out loud! And do this continually as you go along.
You are not just copying your model. Your job is to pull out those elements that tell the story, simplifying, and triaging if you need to. And since no one but you will see the original cap, you do have some artistic licence!
I've called these initial videos, 'First pass'. A good way to see this carving, indeed most carvings, is a series of passes that become more and more refined. The first stages are usually called 'bosting' or 'bosting in' by carvers; it's the same thing: big picture, getting the main shapes sketched out.
Here we have some guides to help us start this first pass from front to back.