I like your question , it never come to my mind to think why does earth have deserts.
My suggestions for you is , first of all it maybe more attractive if you would change the title of the question to "why does earth have deserts?"
second of all i would recommend you another link to the map :
The Sahara desert :
The Sahara is the world’s largest hot desert and one of the harshest environments on the planet. It is third largest desert overall after Antarctica and the Arctic, which are cold deserts.
At 3.6 million square miles (9.4 million square kilometers), the Sahara, which is Arabic for "The Great Desert," engulfs most of North Africa. The desert covers large sections of Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Western Sahara, Sudan and Tunisia.
at last this link of the top 10 largest desert in the world it would be fun to watch it after they solve the question.
The topic of the question is very interesting. the connection between the question and the video is excellent. However, I think that the purpose was to build a video by yourself and I think that your point on the map does not help so much to understand why there is deserts o earth ( It does not explain about the Hadley cell), I suggest to add another video or stimulation that help to understand the hadley cell better.