The icon of the Nativity of the Thetokos presents to us the central figures of Saints Joachim and Anna, Mary's parents, and the Mother of our Lord as an infant. Saint Anna is in the middle of the icon with her right hand extended toward her daughter. Likewise, Saint Joachim, Mary's father, is gazing upon the young child with his right hand extended toward her. Anna is surrounded by attendants who have assisted with the birth.
The icon directs attention to Mary as the central figure in this feast . It also acknowledges the joy that was felt by Joachim and Anna as new parents with a child received through a promise from God. The liturgical texts of the feast acknowledge this joy and confirm the special role of Mary as the Mother of the Incarnate God, Jesus Christ. In this event, another step is made in sacred history in preparation for the entrance of Christ into the world. The central figure of the feast, the Theotokos and Ever-Virgin Mary.
The icon and the feast also acknowledge a transition from barrenness to life. This was but another foreshadowing of what would be offered through Christ, the transformation from death to eternal life.
http://www.goarch.org/multimedia/audio/nativitytheotokos/kontakion