One of the sisters in my community who spent some time in Rome told me this. For many years Sr. Gesualda, a Daughter of St. Paul in Rome, served as a secretary in Cardinal Ratzinger's office at the CDF. He knew that this sister had a great devotion to the Blessed Mother. So he would often put on her desk any pictures of Mary that he had. I think this story shows an interesting personal side of the cardinal, now pope, Joseph Ratzinger.