Isolation transformer: shaver socket in the bathroom

Today's big question has been about these shaver sockets. Why are you allowed to plug in shavers in the UK when nothing else is allowed to be plugged in? It turns out that there are two parts to the answer. The first is to say that the socket is a special type of transformer. It has a 1:1 turns ratio so it doesn't change the voltage or current. However, the secondary is electrically isolated from the primary - they are connected by a magnetic field not by wires. The primary circuit is earthed. You are also earthed because you are standing on the ground. So if you touch the live in the primary circuit there is a complete circuit from the live to your hand down through you to the earth and through the earth back to the live. Current flows around that loop and hurts you. But the secondary circuit is isolated from the primary. It is not earthed. Even if you touch the live, no complete loop circuit back exists so you don't get a shock. So this is a safety transformer. The second thing is that they are given 200mA fuse so the maximum nominal power rating = 0.2 x 230 = 46W. It limits the power so most devices couldn't be used without blowing the fuse.