@barnosch
I think the reasons are:

1. its wireless, i can put it easily to any location
2. it enables light of the mirror
3. I already had it, and didnt want two sensors

@barrysmallgoods
thank you for the great suggestion. Funny thing is that I have that power plug installed for the light on the mirror, but I havent’t thought of adding a splitter and connect the monitor to it as well.

I was wondering if someone has the Xiaomi movement sensor (and Hub), and is able to connect Magic Mirror to it. Ive.seen some temperature module, would be really cool to use this sensor to turn on the monitor.