I just installed this mirror, searched the answer and solved it. The mirror of IKEA is very well designed, and the screw below turns in the opposite direction to the screw above. So don't be afraid, twist it hard, get your arm stuck in the mirror and force the screw up and down at the same time, and you can screw it in by force. This design screw will not trip and is waterproof, because this mirror can be used in the bathroom. After screwing it in completely, I was surprised at its firmness. Don't be afraid of being damaged. I read it carefully. They are all steel structures, and all positions are far more powerful than the plastic barrier below. It is impossible to screw out the steel.

In addition, be sure to remember to tear off the sticker, slowly, without leaving any glue. The base is really bright, like a mirror. The IKEA sticker is too thick. If you don't tear it off and twist it, it will hinder the gasket and the gasket will be deformed. Mine has no deformation at all, and it looks almost as complete as the photo. The whole mirror is very, very strong, it doesn't shake at all, and the screws won't loosen slowly. Nice design, this design is really the first time I have seen it.