Zephyros
I agree, there doesn't seem to be any glass missing. The similarities to the slits are striking, however, but I can't seem to resolve any significance to that. My first thought was that these were Boaz and Jachin, the two pillars present on the Priestess, yet the Moon seems a better fit, as it really does look like that card in miniature up there, as if captioned. The illusory nature of that card would seem to suggest that here is the result, swift Mercury being reined in to the purposes of slow and plodding Taurus in an unbalanced position on the Tree: no comfort in materialism here.