I want to know the answer to the following question:
What does Mary stand upon in this symbol?
All the background I'm provided with is that "The popularity of this particular representation of The Immaculate Conception spread across the rest of Europe, and has since remained the best known artistic depiction of the concept: in a heavenly realm, moments after her creation, the spirit of Mary (in the form of a young woman) looks up in awe at (or bows her head to) God.". Is that enough to answer the question?
Answer: no