Welcome to YT!! Your Bruin and Nico are just beyond cute! I had to laugh when I read your question, because my little Mango does exactly the same thing, but it's usually when she's really excited about something, and she does this little "happy dance", bouncing around and then kicking out her back legs.... we call this the "Mango Tango".
It has provided months of entertainment - we laugh every time we see it.
Lauren