He and his wife have 4 kids - the oldest is a son, then a daughter, then twin boys. So he decided he wanted the balls the juggler was juggling to represent his kids!
The blue ball is his eldest son, the pink is his daughter and the green balls are the twins! He chose to have the "biggest handfuls" as the green balls - as that was definitely the twins!
Isn't it a great idea.....Tomorrow I'll show you his other family piece.