Personally I find most of these metallic covers unattractive. And for the purposes of prayer would rather see the painted image than what is in effect, for the most part, a relief carving in metal. I am always frustrated by the fact that some parts of the original image are hidden and find myself trying to work out what the image underneath looks like (if indeed it is really there!) rather than allowing my attention being taken to the real saint in heaven. That is very likely my weakness and many I’m sure will have a different reaction.
The key elements that make an icon an image worthy of veneration are that the characteristics of the person are captured and that the name is written on it. So when covering, either some parts of the icon that characterize the person, such as the face, must be left visible; or else the cover must be panel beaten into a image that bears those characteristics that are in the original icon but now hidden. thus the cover becomes an integral part of icon. If the characteristics of the icon are not visible then it is not an image worthy of veneration.
There is a danger, it seems to me, that the use of these covers might cause some to infer, incorrectly, that the icon is holy in the wrong sort of way: one that considers it to be a grace-filled object.
We need, I think to go back to the great 9th century Father of the Eastern Church, Theodore the Studite. He is the Father who provided the theology that finally cleared up the iconoclastic controversy of this period.
An icon does not, says Theodore, participate in the nature of the individual – that is, it does not contain any aspects of human nature or divine nature, it is just an image. Therefore the relationship between the image in the icon and the saint in heaven is established by our perception and apprehension of the likeness. That relationship cannot exist in a way that involves the icon, therefore, when we are not apprehending the likeness portrayed in the image. A crucial role in establishing this relationship between icon and saint is played by the imagination, which takes our thoughts from image to saint.
Consistent with this, Theodore states (echoing earlier Fathers Leontius of Neapolis and Patriarch Germanus) that once an icon is worn and has lost its ‘imprint’ (charakter), it will without hesitation be thrown into the fire “like any useless piece of wood." If Theodore considered the icon as such a grace-filled object, he would not dare to suggest that it be burnt.
Theodore sees the sacredness of the icon entirely in its character, its portraying depiction. In this sense, if a characteristic is not visible, it is not portrayed. Putting a metal cover on an icon that did not have the characteristics and name of the saint on it, would be the same as covering the icon surface with a couple of coats of house paint. If the image has been rendered invisible, it might as well not exist.
For those who are interested, I have written at length about Theodore and his impact on the iconoclastic controversy here.
Above, St George killing the dragon; below a St Nicholas and a Mother of God have covers that afford physical protection and reveal more of the original. I prefer this balance of the latter two.