I can not judge about the reasons for the behavior of this child by a video.
But i know it from observing my own children, that there might be some memories of former lifetimes in children's minds as long they are not older than 3 years.
When we were about to get a piano into the house, my 2 year old boy said very pleased: "Ah, FINALLY i can play piano again!"
Unfortunately he refused to get lessons, but sometimes he plays just for to relax anything what comes into his mind. It always sounds very nice although he doesn't know how to play really.
Metta, Karuna, Mudita, Upekha
*** May these efforts be helpful.
Djang chub sem chog rinpoche, ma kye pa nam kye gyur chig. Kye pa nyam pa me pa yang, gong nä gong du phel war sho._()_**