The icon's visual conventions and techniques create symbolic landscapes within which the viewer strives to perceive the inner, the hidden. ICONS & THE MYSTICAL ORIGINS OF CHRISTIANITY by Richard Temple is an excellent read.
My favorite of these visual conventions is the Virgin depicted with tiny feet to show that in her unearthly purity she hovers above the ground and barely touches it.
Here is my take on Christ the Ruler and Sustainer made with pastel and gold ink on Stonehenge paper. His asymmetrical eyes point to the humanity and divinity of Jesus focusing on two different worlds. Seen and Unseen. The pastel medium is one of the most accessible forms of almost pure pigment.