What a shame! As often happens, the author of the video doesn't deign to answer the questions that are asked. For those who need it (like @KOMODENU88 ) from this link it is possible to understand the structure of Bona's lick ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-0spxI5Dl3qA.html