What happens when you have a baby?

I had coffee with a friend and we disgussed kids, people with kids and the fact that we don't have kids. And one thing both of us were astonished about was the phenomenon on facebook. People who have kids, oooops I just realized I'm gonna step on a lot of toes here, but here it goes, exchange their profile pictures into a pic of their kid.......WHY? Maybe the ones who do and did could enlighten me? I totally understand the pictures where the kid is with you, because it is still such a big part of your life. But only the kid??? Did you disappear once you had the child? I want to think that you just get one role more. You become the mother/the father. I don't want to be synonomous to the offspring. I still want to be me. Although I would probably be ready to sacrifice everything, probably including my life for it/them.