This is the result I get from the small image you shared, starting with the line art preset and increasing the threshold:

With a better quality image it would produce a higher fidelity trace.
There's nothing else you can learn from this video. That's all there is to it. There is no creativity involved, this is just learning what buttons and sliders do what. You're better off reading the instructions and experimenting on your own images if your goal is to learn the image trace panel.
OK I have solved the issue. Original JPG image is in FREEPIK. It is coming. I do not know why my PNG screen shot did not produce the result.