This is best understood by watching the video and listening to it for yourself. But if for some reason you can’t do so well the difference is that typing without a deskmat causes the sound of your keyboard to resonate through your whole table and it creates a echo-ey noises that alot of people don’t like. To remedy that, people use thick deskmats to dampen the sound to isolate it. There’s no right or wrong to this, just go with or without according to whatever sounds best to you.
