Instead of the usual metal ball to whisk the powder, they include this weird plastic mesh that goes at the top of the inside of the shaker, complicating a rather simple, tried-and-true design.
The top of the shaker that you screw on is never easy to screw on and gets tight too quickly before the shaker is properly sealed, for icing you to unscrew it and try again. And even when seemingly sealed, I’ve had liquid splash around when I start shaking the bottle.
L shaker