We are used to seeing something familiar on the surface of the canvas. Something which can be adequately analyzed by using familiar categories, like for example shapes, colors, shadows, propotions. Looking at the icon we see a completely different depiction. That is why we cannot use this kind of analyses on icon painting. The icon does not try to convince people that something that is painted in it is a real thing. Icon painting represents unreal and ideal things. To be able to appreciate icon painting we must be ready to see something that can be unacceptable in ordinary art.
Iconography does not follow the rules of proportion but it is propped with proportions of faith. My firm opinion is that only a religious and pious person can become a true master of icon painting.
