For years the conventional wisdom has been for Sellers to take down and pack away all their family pictures. The thought was that this would help enable potential Buyers "Picture" themselves living in the home without the distraction of someone else's stuff. To this day I get asked by Sellers whether or not they should remove their family pictures.
My answer? It depends. If the walls are covered with pictures I will suggest they keep their most treasured photos up and pack the rest. This is just part of the home "De-Cluttering" process. Most of the time, though, I say absolutely not. Never have I had an agent say to me, "We really liked your listing but we can't buy it because the Seller has pictures on the walls".
As long as the number of pictures in the home is not over-whelming, I say leave them up. The Seller still has to live in their home while it is being marketed and it is stressful enough during this time. Let's not add additional stress to their lives. I will bet the potential Buyers will be able to focus on your home just fine!