Why can I hear the sound inside the camera when my Huawei p40 is shaking, and the sound is not small?

This is probably because there are pieces of parts in the camera of your mobile phone, so the camera has abnormal noise, because there is space in the camera, but the volume is relatively small, and it is a very closed space, and it is difficult for things outside to enter, so it is likely to be a small part inside. I suggest you don't check it yourself, but it's safer to go to the after-sales service of your mobile phone.