The figure in the icon is not meant to represent literally what Peter or John or any of the apostles looked like, or what Mary looked like, nor the child, Jesus. But, the orthodox painter feels, Jesus of Nazareth did not walk around Galilee faceless. The icon of Jesus may not look like the man Jesus two thousand years ago, but it represents some *quality* of Jesus, or his mother, or his followers, and so becomes an open window through which we can be given a new glimpse of the love of God. 
Madeleine L'Engle, Walking on Water: Reflections on Faith and Art
apostles, art, iconography, icons, jesus, love, painting