IMO distraction from your work where how interesting your task at hand vs immediate facebook check.I would relax and get to see what I am doing and how its interesting/fullfilling/fun/silly etc and lets the grip of immersion take over you. So to reiterate is I don't think social media is distracting but rather working lives of most office workers aren't as exciting(like friends windsurfing) and social media can be a demotivational poison at that point. I am guilty of letting social media reign over me on bad days, but on really good days it is the task at hand has control of my attention and rest of facebook/tv/movies/games noise has selfish demanting and yet weak overtones...