AH HA! So turns out you need to install as root - the regular pi user doesn’t have enough permissions to install socket.io which is a dependency of electron…
The manual install instructions should be updated to state
sudo npm install
npm start
Damian
Yeeesh that is dark - although even the pic with the normal camera is really dark. Much less contrast than I was getting, perhaps you do have a bad camera as the quality definitely shouldn’t be that poor.
This is where the camera is setup - try adding
camera.brightness = 90
https://github.com/paviro/MMM-Facial-Recognition/blob/master/facerecognition/picam.py
Worth a shot 
@Synthic That is frustrating…
I think the facial recognition module uses python-picamera to talk to the camera, are you able to tweak the configs somewhere in order to up the brightness?
https://www.raspberrypi.org/documentation/usage/camera/python/README.md
@Synthic Infrared is blocked by cameras anyway so that wouldn’t make a difference. The only thing the camera cares about is visible light so if you are able to see through the mirror you are using then there is no reason that the camera shouldn’t be able to do the same thing regardless of what material the mirror is made from.
I too have the basic PiCam located behind the glass and it works perfectly. Does your cam work without the glass in place?
@Synthic We as using the picam behind the mirror without any issues. If you place it right behind the glass do you see the same thing or only when it’s in the hole you drilled?
AH HA! So turns out you need to install as root - the regular pi user doesn’t have enough permissions to install socket.io which is a dependency of electron…
The manual install instructions should be updated to state
sudo npm install
npm start
Damian
Getting the exact same thing here too - Raspberry Pi3 - any ideas?
16 error Linux 4.4.34-v7+
17 error argv “/usr/local/bin/node” “/usr/local/bin/npm” “start”
18 error node v6.9.4
19 error npm v3.10.10
20 error file sh
21 error code ELIFECYCLE
22 error errno ENOENT
23 error syscall spawn
24 error magicmirror@2.1.0 start: electron js/electron.js
24 error spawn ENOENT
25 error Failed at the magicmirror@2.1.0 start script ‘electron js/electron.js’.
I had tried using the latest node too - I downgraded to v6.9.4 just on the off chance it was a versioning thing but as you can see no go.