It is a pose to remove dirt that is attached to the hand.
I think that it can also be used for the scene to clap, to make a big rice ball, to chant the magic, and to trigger it to the center of both hands.
手に付いた汚れを落とすポーズです。
他にも拍手、大きいおにぎりを作る、魔法を唱えて両手の中心に発動させるシーンにも使えると思います。





