From 0:00 until 0:08 : No winging scapula, back support
From 0:08 until 0:28 : Winging scapula, no back support
You probably heard teachers say: "keep your shoulders down". I agree with the idea but this is not "that" simple... you might end up with pain in your trapeze and tendonitis in your elbow.
Be careful, with scapula winging...
Of course lifting too much your shoulder is not good, but if your shoulderblades don't have good support, putting your shoulder down can be as bad as the opposite.
Your shoulder blade must find support from your back muscles because if not, you might get pain in your trapeze and neck. Your sound will not project as well as because the weight of your arm will end up in your elbow. It often causes tendonitis.
Having great support from your back muscles doesn't mean your scapula will not move. If the scapula is attached by surrounded muscles and not a joint means more possibilities in movement.
Once you built good muscle support, you can add as much weight as needed on the string, your whole body is connected, from your feet to the tip of your fingers.