That said, it will be covered in an upcoming tutorial which covers things like installing pm2 to auto start npm, and remote access. Remote access is different for everyone, there is no fixed way of doing it. My network isn’t the same as yours, or others.

from npm-debug.log:

0 info it worked if it ends with ok
1 verbose cli [ '/usr/bin/nodejs', '/usr/bin/npm', 'start' ]
2 info using npm@3.9.5
3 info using node@v6.2.2
4 verbose run-script [ 'prestart', 'start', 'poststart' ]
5 info lifecycle magicmirror@2.0.0~prestart: magicmirror@2.0.0
6 silly lifecycle magicmirror@2.0.0~prestart: no script for prestart, continuing
7 info lifecycle magicmirror@2.0.0~start: magicmirror@2.0.0
8 verbose lifecycle magicmirror@2.0.0~start: unsafe-perm in lifecycle true
9 verbose lifecycle magicmirror@2.0.0~start: PATH: /usr/lib/node_modules/npm/bin/node-gyp-bin:/home/pi/MagicMirror/node_modules/.bin:/usr/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/games:/usr/games
10 verbose lifecycle magicmirror@2.0.0~start: CWD: /home/pi/MagicMirror
11 silly lifecycle magicmirror@2.0.0~start: Args: [ '-c', 'electron js/electron.js' ]
12 silly lifecycle magicmirror@2.0.0~start: Returned: code: 1  signal: null
13 info lifecycle magicmirror@2.0.0~start: Failed to exec start script
14 verbose stack Error: magicmirror@2.0.0 start: `electron js/electron.js`
14 verbose stack Exit status 1
14 verbose stack     at EventEmitter.<anonymous> (/usr/lib/node_modules/npm/lib/utils/lifecycle.js:245:16)
14 verbose stack     at emitTwo (events.js:106:13)
14 verbose stack     at EventEmitter.emit (events.js:191:7)
14 verbose stack     at ChildProcess.<anonymous> (/usr/lib/node_modules/npm/lib/utils/spawn.js:24:14)
14 verbose stack     at emitTwo (events.js:106:13)
14 verbose stack     at ChildProcess.emit (events.js:191:7)
14 verbose stack     at maybeClose (internal/child_process.js:852:16)
14 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:215:5)
15 verbose pkgid magicmirror@2.0.0
16 verbose cwd /home/pi/MagicMirror
17 error Linux 4.4.14-v7+
18 error argv "/usr/bin/nodejs" "/usr/bin/npm" "start"
19 error node v6.2.2
20 error npm  v3.9.5
21 error code ELIFECYCLE
22 error magicmirror@2.0.0 start: `electron js/electron.js`
22 error Exit status 1
23 error Failed at the magicmirror@2.0.0 start script 'electron js/electron.js'.
23 error Make sure you have the latest version of node.js and npm installed.
23 error If you do, this is most likely a problem with the magicmirror package,
23 error not with npm itself.
23 error Tell the author that this fails on your system:
23 error     electron js/electron.js
23 error You can get information on how to open an issue for this project with:
23 error     npm bugs magicmirror
23 error Or if that isn't available, you can get their info via:
23 error     npm owner ls magicmirror
23 error There is likely additional logging output above.
24 verbose exit [ 1, true ]

EDIT:
Totally forgot that i was SSH:ing :/
DISPLAY=:0 nohup npm start & Worked like a charm!

Would be nice to edit the Setup guide with that ;)