That was one of my 1st theories 2, but I seriously have doubts bout it now coz you wouldnt even need that 2 navagate your way around a romote.

plus when when you press any button on a mobile all buttons are highlighted with a soft glowing light.

Then I was thinking that it might be a reference point for blind people, but thats a bit far fetched (Its mad the kinda sh1t you'll think up of when your stoned)