After reading "The Origins of Judaism, An Archaeological Historical Reappraisal" by Dr. Yonathan Adler, I understood that the practice of not making images of God/gods changed rather abruptly after the Hasmonean revolt. Ever since, the ban on making graven images of God has become an inherent part of Jewish theology and tradition.
The Second Commandment is constantly cited as the source for such a prohibition, but the text stresses "אֱלֹהִים אֲחֵרִים עַל־פָּנָיַ" ("other gods before me") and, regarding icons and images, "לֹא־תִשְׁתַּחְוֶה לָהֶם וְלֹא תָעָבְדֵם" ("thou shalt not bow down to them, nor serve them"). Similarly, all books of the Torah and Prophets mention idols of other gods as abomination.
I flipped through Rambam's Hilchos of Idolatry but didn't notice him mentioning anything related to images of YHWH/El/Elohim and worshipping YHWH specifically "through" them like the Christians do with the paintings of Michaelangelo (I refer to "God the Father", not Yeshu).
I wondered, if a (not-necessarily-anthropomorphic) statue of YHWH were placed in a synagogue (with a clear inscription "שִׁוִּיתִי ה' לְנֶגְדִּי תָמִיד") and another person was "worshipping" YHWH and bowing to this statue by reciting the Amidah prayer, what would the theoretical punishments of the sculptor and the worshipper be in Jewish Halachah?