Right foot movement? You mean where it darts back/sideways towards the dugout as he balances after his swing? Like Jose Altuve's? Mike Trout's? Kris Bryant's? Clint Frazier's? Mickey Mantle's? Roberto Clemente??? It's not a conventional movement. But as evidenced above, has nothing to do with how good he could be. It's called a 'scissor kick'.
Hmmkay.