Here we have the component responsible for shaking things up—the Taptic Engine, also known as an electromagnetic oscillating linear actuator.
Compared to the shakers of yore, this is a much thinner design, but it's also longer.
Even this smaller engine takes up a lot of room in this tiny device—room that could have gone to a bigger battery, but Apple seems to feel physical feedback is very important.
Android device makers? Not so much.