This is the icon most likely to confront any visitor to an Orthodox church or cathedral, as it is usually present in the upper part of the altar, the focal point of any church. It is also one of the most ancient Christian icons, being found in the first-century catacombs where the early Church worshiped secretly. What does this image show, and what is behind its name?
Therefore the Lord Himself will give you a sign:
Behold, the virgin shall conceive and bear a Son,And shall call His name Immanuel (Isaiah 7:14).
As for the use of this image, or variants of it, above altars in church, this is related to the New Covenant, Christian, church being a renewed version of the Old Covenant, Jewish, Temple. In the Jewish Temple, as described in the Bible, there was the Mercy Seat. Flanked by cherubim, above the altar, and inside the sanctuary, it is within the Mercy Seat that the presence of God was manifest every year to the priests. Now, of course, God is manifest to us all in the person of Jesus Christ, and so Mary – within whom the glory of God was manifest – becomes the “new” Mercy Seat. Indeed, in the first Icon at the top of this post, she is even flanked by Cherubim, as the Mercy Seat was. But unlike the Mercy Seat of the “Old” religion, the Mother of God, and her Son, are clearly visible and manifest to everyone who enters an Orthodox church.
The people who walked in darkness have seen a great light; those who dwelt in a land of deep darkness, on them a light has shined.
For unto us a Child is born; to us a Son is given.
And the government shall be upon His shoulder, and of His peace there will be no end. And His name shall be called the Messenger of Great Counsel, Wonderful, Counselor, Mighty God, the Everlasting Father, the Prince of Peace, the Father of the World to Come.
God is with us! Understand this, O nations, and submit yourselves! For God is with us!
(from the Song of the Holy Prophet Isaiah)