Returning to the Milk-giver icon:
A few of the many hymns which deal with the matter, from a variety of Orthodox services:
Without seed you gave birth in time to the timeless Son of the Father, O Mother of God. O strange wonder! you nourished Him at your breast while remaining a virgin.
Search the Scriptures, as Christ our God said in the Gospels, for in them we find Him brought to birth and wrapped in swaddling clothes, nursed and suckled, accepting circumcision and carried by Symeon, not in imagination, but in truth appearing to the world. To Him let us cry, ‘God before the ages, glory to You!’
All of us, the generations of men, bless you as the Virgin who, alone among women, gave birth without seed to God incarnate; for the fire of the Godhead made His abode within you, and you nurtured the Creator and Lord with milk as a babe. Therefore, we, the race of angels and men, cry out to you together: Entreat Christ our God, that He grant remission of offences to those who with faith honor your all-holy birthgiving.
All the choirs of Angels were amazed, pure Virgin, at the dread mystery of your child-bearing: how He who by His will alone upholds the universe is held as a mortal in your arms, and how the Pre-eternal accepts a beginning, and He who nourishes everything that breathes by His ineffable goodness is suckled at the breast. And as they praise you as truly God’s Mother, we glorify you.
The Creator of the ages, who fulfilled the law as a babe of eight days, is circumcised in the flesh; He is wrapped in swaddling clothes as a mortal and He is nourished with milk, who holds all things by His infinite strength as God, and ends them in an instant.
Icons are the visual counterpart of hymns, and both represent and proclaim what the Church teaches and believes.