Same images as #505 as that recipe illustrates the problem quite well: Chemical Stacks (in this case the Water Vapor "gas") aren't being rendered properly as it seems.

For reference, here's Mekanism's ChemicalStackRenderer implementation:
https://github.com/mekanism/Mekanism/blob/1.16.x/src/main/java/mekanism/client/jei/ChemicalStackRenderer.java

Interestingly enough, contrary to that other issue and unlike FluidStacks, the "amount" of ChemicalStacks produced is being rendered correctly here, though this is not intended as Mekanism actually wants to show the full tank here from what I remember: