To understand the Dormition (falling asleep) of the Theotokos, it is helpful to study the icon of this Feast. Mary is reclined on a bier as she would be upon her death and at her funeral. Standing over her is the resurrected Lord Christ, which we know because of the radiant light surrounding Him and the host of angels that accompany Him. Also present are the Apostles except St. Thomas, who was not there. Christ is holding her soul in what appears to be a baby in swaddling clothes. This represents her birth into eternal life.
At the right near her head is St. Peter weeping and censing. At her feet is St. Paul and all around are the other Apostles. All are weeping.
In some icons of the Dormition (though not in the icon depicted here) there appears a small pagan character who attempted to upset her bier, but an angel comes to smite him. It apparently is symbolic of the controversy surrounding the Council of Ephesus over how we properly understand the person of Christ. The Orthodox teaching was expressed with the term “Theotokos”—birthgiver of God—with the intentional emphasis on "God" as opposed to “Christotokos.” The implication of the latter expression was that Mary did not give birth to the divine Son of God, but to a mortal. The upsetting of the bier, were it not interrupted by the angel, would indicate a foiled attempt to upset the correct and official teaching of the Orthodox Church.
The icon can also be used as an image of what happens to us at our death. When we die, the body falls asleep and is placed in a cemetery, which literally means place of sleep, to rest. Our souls also are take to heaven by Jesus. At the glorious second coming, He will also raise our bodies to be reunited with our souls. Thus we shall be with the Lord forever.