--The title Ancient of Days, if we want to be consistent, should apply to each Person of The Holy Trinity (none is more God than the other). You cannot see The Father because He is never visible (not even in the Age to Come). The Father can be known, interacted with, but not seen. What you see is Christ (the Icon, the Logos). And this is possible in The Holy Spirit.
--Clearly, you can never depict The Father in iconography because it cannot be a fact, and there's a canon against that.
--The Ancient of Days is really something that was more fitting to The Old Testament. It helped people visualize things back then. Honestly, God is never an old man with a beard; this would come close to the Human Nature of Christ, but He's not old. Nowadays, we have higher revelations such as The Uncreated Light, that God is immaterial spirit, and we are even called to give up any way of imagining God because He cannot be seen in His Essence (and this includes Christ's Divine Essence). Only His human (physical essence) can be actually seen. But, God CAN be known and seen by our nous (as Spirit). That's what we are called to, our whole struggle in The Church, to know God as He is.