Also, after showing the animatic to Amy, one of my friend, she gave some advice on the timing. We adjust the time for this shot, make the oldman eye-closed part longer.
And last time, when Vera rerender the old man part, the outcome's color is dismatch with the old one. We match all the light and their relationship and cannot find the difference. At last, we figure out that it is because the environment color of the Camera. We never know that this element will affect the final outcome, because that should be png, alpha.