Thanks! I find the mythological aspect of it fascinating. I'm sure there're other interpretatios, but from the site you shared
Almost all historical sources believe that the Ball & Claw design was derived from the Chinese: a dragon’s claw grasping a crystal ball, or a pearl, or sometimes a scared, flaming jewel. In Chinese mythology, the dragon (Emperor) would be guarding (with the triple claw foot) the symbol (ball – for wisdom, or purity) from evil forces trying to steal it.
Another interpretation is that the ball symbolizes a polished river stone being held firmly by a crane, who stands diligently over her nest. Resting on one leg, with the stone held in mid air by the other, the mother crane watches over her young and would quickly awaken if she were to fall asleep and drop the stone.