My guess, nothing.
We miss so much when we focus our attention on recording life, rather than living it. What if the disciples had tried to write down every miracle Jesus performed, instead of listening to Him and following Jesus' instructions? What if your mother couldn't focus on pushing you out because she had to catch up on the latest gossip around town? That may have been a little extreme, but you get the point.
Life is full of surprises and mysteries and thrills and excitement and wonder. You are bound to miss something when you are glued to your phone all the time. Many will say that communication, finances, and intimacy are the top 3 killers of a marriage. I am still a believer that those are a death sentence when one or more are lacking or severely damaged. I am also starting to believe that the abundance of electronics can also affect a person's relationship (professionally and personally). I will spare you my rants, for now.
But I will leave you with this bit of advice. At some point in your relationship, you will begin to question the state that it is in and the direction it is heading. Instead of turning to outside sources for joy and comfort (i.e. Facebook), turn to the person who has been by your side for so many years. Check-in with them instead of with social media. Like something that your wife or husband said by actually telling them, to their face. Whatever score you are trying to get or funny post you are trying to see will be there tomorrow. Your spouse may not be there when you finish updating your status for the 10th time in 8 minutes.
Lesson: choose your phone time wisely. There was once a time when we did not have instant access to the world, and we did just fine. It's okay to unplug. Otherwise the battle of the phones, won't be the only battle of the night.