the reason why people sometimes bite the xiaolongbao skin which is basically a hole, it is because xiaolongbao is normally served straight off steamers so it is super fresh with lots of steam - very hot! the hole allows the temperature to go down a bit before it goes into mouth. Other than thats, true, some people loved tasting the soup from inside before eating the whole lot.
I sometimes drink the vinegar after eating the dumpling/xiao long bao hahaha. Where is this restaurant? Love your food videos, eeek. so much love for you two girls, wish I could meet you guys when I come down to Melb xxxxx