Here, we see a woman, the Mother of God, encircled by a short and famous prayer: "O Mary conceived without sin, pray for us who have recourse to thee." Being conceived without sin - often referred to as her Immaculate Conception - means that from the beginning this woman was full of grace.
Mary stands on a globe, the world. Around her feet a twisted serpent, the devil, struggles for mastery. It's a conflict between good and evil. Satan's is a world of darkness and disgrace: Mary's - a world of light and grace. But hers is the victory, won by Christ - the light of the world. So we see the light and grace of Christ flowing from her hands; and those who choose grace rather than darkness turn to her for help: "pray for us who have recourse to thee."