Also, siamese twins helps to illustrate to us that somebody can have one or more mind and yet be one being. Granted, God is not exactly like siamese twins, but it should help you to understand that such things do exist in this physical universe. Also, who exactly is the Son talking to? Well, God the Son is talking to God the Father. Does God the Son need to pray for the Father to hear God the Son? Well, God the Son suppressed His Omniscience in the Incarnation. See Philippians 2:6-9 NLT (New Living Translation). However, does this mean, God the Son could not commune except by prayer? Well, the Scriptures say that Jesus did not need to pray for the Father to hear him. Read the story of the resurrection of Lazarus. Jesus prayed as an example to others.