The key words in Mor's statement are "in the proper degree". The iconographic portrayal of the Mother of God as minister of the Eucharist is not in the proper degree, far from it. It proclaims her as being something she never was, and something she still isn't.
But this begs the question about the original vision, LBK. If the monk in question was granted this vision in order to teach him a particular lesson, why not depict it as it occurred? Why does he get to see
our Lady distributing Communion and describe the vision to others, and yet it can't be painted? Surely God is in his heaven, knowing what he's doing? Or does the vision not come from God?
What I know is that icons are to depict what is in harmony with what the whole Church teaches. I also know that visions are to be regarded with great caution, irrespective of whether they are seen by saints, monastics or laymen. It is one thing to show in an icon the Mother of God handing back St Nicholas of Myra's omophorion which had been stripped from him at the Council of Nicea, and quite another to show her as minister of the Eucharist.