Good question. Many football players and popular British-Kosovan singers like Dua Lipa and Rita Ora create an eagle (with two heads) with their hands. With this symbol, Albanians around the world (92% of Kosovo is Albanian) show their pride of being Albanian. You can see the eagle on the Albanian flag as well.
Some people try to ‘criminalize’ this symbol, like when Xhaka and Shaqiri scored both goals against Serbia at the World Cup 2018. But it is just a peaceful and friendly thing to do.
So, if you want to be cool in Kosovo and make friends: do your hands like Rita and Dua.