Note how the different ranges of light shining on each of these photographs of the Holy Face effects one's perception of the image. During my visit to the Shrine of the Holy Face I was amazed at how radically the image can seem to change from moment to moment.
With the light shining through the eyes there is a corresponding intensity of the wounds on the face. More than anything the glowingness of the wounds on the face astonished me.
In this photograph one can begin to see the transparent nature of the image/cloth when light shines from directly in front or behind.