That picture sort of says it all doesn’t it? The halo of the child is reduced to make room for the full halo of the “queen of heaven”. The child is secondary to the “queen of heaven” just as it is in all pagan worship.
There is nothing about sizes of haloes which has anything to do with amount of honor. In this the present example, the "Queen of Heaven" is secondary and even on an incomparably lower plane, as the creature is lower than the Creator, and the finite lower than the Infinite.
The fact is, that God alone is holy; and other persons (or even places, things, or ideas) are called "holy" only in a secondary and completely dependent way: "Holy Saints," "Holy Bible," "Holy Angels," "Holy Songs and Canticles," "Holy Manna," "Holy Mary."
Mary is the mother of Jesus Christ, who is God and who has come in the flesh. As a human mother, she is bigger than her infant. The picture illustratres that. And that's all that "size" has to do with it.
I am glad you have given me the opportunity to explain this. Otherwise, you would have long retained a mistaken impression.