Following the Great Schism, what replaced the ecumenical councils' canons on art?

There are much simpler ways to frame this question, but for dramatic effect, consider the [Adoration of the Mystic Lamb](https://en.wikipedia.org/wiki/Ghent_Altarpiece) which was finished in 1432 and the [Qunisext Council](https://en.wikipedia.org/wiki/Quinisext_Council) . In the roughly 700 years separating these two events, much changed in terms of the Church's institutional setup, including the Great Schism. The early ecumenical councils laid out detailed doctrines to govern the appropriate depiction of Christ in visual media. Among the most well-known from the Quinisext Council is canon 82, which bars artists and court artisans from depicting Christ as a lamb, and further asserts that the only canonical representation of Christ is the human form. Essentially, this canon had came about from the ongoing debates on Christology at the time -- whereby the church fathers took the side of a dual-nature. Of course, that Christ did have a human nature was critical for the soteriological function of his blood and sacrifice. Thus, if we were to cherry-pick the Adoration of the Mystic Lamb, then, clearly it would be incompliant with this canon, as the lower panel depicts just such a lamb. Though there is reason to think that the artist was not unaware of the legacy perspectives around this category of iconography: the lamb has a human-like face and explicitly depicts the lamb as having stigmata, with blood flowing into a chalice.

Question

The Catholic and Protestant theological view on the proposon having a human aspect remains consistent with the stance of Fathers of the Quinisext Council, however, in the following centuries, strictures around lamb iconography has loosened, why is this likely the case and what if anything replaced the canons on iconography laid out in the Quinisext Council?