The Annunciation to the Blessed Virgin Mary by the Archangel Gabriel. This is also considered the Incarnation of Jesus. Those letters "ICXC" are an abbreviation of the Greek name of "Jesus Christ" ("IHCOYC XPICTOC"), hence she is conceiving Jesus by the Holy Spirit and power of the Most High. ^_^ That's why the light is going towards her. Her arms are crossed in humility as if she was saying "Behold the handmaid of the Lord; be it done to me according to thy word". Gabriel the Archangel and Blessed Mama Mary, pray for us! O:)