Ah, they're probably coming up next! I don't recognise the performance off the top of my head, but doing ballet is HELLISHLY INTENSE and doing it without your muscles througly warmed up is just asking for injured tendrons. In between scenes the dancers literally can't sit still for too long or their muscles will cool down, or worse, cramp up, and if they're not changing costumes they're usually stretching, vigorously massaging their legs and, like here, bouncing around to the tune.
So this is a perfectly natural ballerina behavior. They're just keeping warm and bonding. 👍
I love how the last line has the exact cadence of a "is the ballerina video cute" blog
these ballerinas are not distressed and this in fact good enrichment for ballerinas when confined outside their natural habitat (the stage)