The only problem I have with it is that some parts look flat/unfinished. (The foreheads, and feet.)
Ah, well that's by design. The "jars" are meant to be filled with a semi-opaque fluid (only way I could make the illusion work). The idea was that those areas (forehead, nose, foot, and much of the back) were the ones pressing against the glass, which means there is no dark fluid between them and the jar wall, which is why they look brighter than other areas.