The Magician represents a snake-oil salesman or performing illusionist who blinds you with sensationalism in order to trick you. He wows you with possibilities but doesn't actually reveal or explain anything (which is the job of the next card, The High Priestess). This card doesn't actually represent a scholar or inventor at all. Less "magus", more "trickster". A stage magician.
If this Shadow reflected something like that, it would represent Marisa's prismatic, "love-colored" magic, and all her comets and stars and orreries and moon-shooting lasers and super-fast speed... a Shadow that dazzles you and distracts you from its true darkness/weakness.
Actually, this looks like one of the symbolism-deficient ones. Sheth meant its design is a shout-out to that first full moon shadow from P3, the one corresponding to the Magician arcana. Y'know, the one most people don't remember because you never got to actually fight it and it looked entirely too much like the mooks in the tutorial battle in any case.