Pendulum motion when riding out of the saddle
You lean the bike in the direction of the leg pushing down? That's quite unusual.
When you sprint, you're effectively throwing all your weight on one leg, then the other. If you were to just stand on one pedal with the bike vertical, you'd flip over the bike from the one-sided force. To counteract this asymmetry, most people lean the bike opposite to the downwards leg.
This also gives you an effectively longer crank for more leverage, as the leaned-up side will have the pedal higher than normal max, while the leaned-down side will have the pedal bottoming out at lower than normal minimum height.