Please tell me who or what you believe a visionary actually sees when he or she encounters the Madonna and Child, given that Our Lord is no longer a babe in arms or a little boy. Does the Blessed Mother appear like this to a specific purpose?
When Mary is pictured in statuary and paintings holding the child (or infant) Jesus, it is a means of artistically depicting her Motherhood of God. A mystic who sees her holding the child Jesus is seeing a visual representation of Mary’s Motherhood of God. Popular devotionals to the child Jesus, such as the Infant of Prague, are a means of recognizing that our Lord by his Incarnation sanctified every stage of life even though during his earthly ministry he died as an adult.
As an analogy, would you keep your child’s baby pictures on the mantle or in your wallet even if your child is now in his or her thirties (or beyond)? Why? Well, because pictures are not only records but also mementos. You keep your child’s baby pictures because it reminds you of the preciousness of his time as a child. In the same way it is okay for Christians to honor our Lord’s time as a child.