I was looking at references of both TNG and Prodigy Jellico to try to make an LD-style Jellico, when I found how they styled his face varied a lot between episodes - I count about 4 significant variants.
For reference, here is TNG Jellico:
This was his first Prodigy appearance in S1 E15 Masquerade:
Definitely a bit yikes, but I also slightly dig the "old man who will bite your hand off if you get within one mile of him" look.
They totally changed his face for his second appearance 4 episodes later, in S1 E19 Supernova Pt 1:
I like this look - it feels very Clone Wars. However, I can see why they might have gotten right of it - it makes it difficult for the face to show anything but aggression.
They dialed back the clone wars for his next appearance in S2 E5 Observer's Paradox:
I think it was also largely the same in S2 E9 The Devourer of All Things Pt. 1:
They might have enlarged the eyes a bit, but I think the other differences are mostly because of perspective differences and facial expressions.
The final, and longest-lived Jellico variant first appears in S2 E14 Cracked Mirror:
This model leans on the more realistic side. This one is probably the most recognizable as Jellico from TNG. It also allows much more expressiveness (not just an aggressive scowl), as seen in these images from E15, E16 (It looks like a different variant, but if you go a bit before, it's actually the same one), and E20:
Overall, I think my favorite Jellico is probably S1 E19, but I can see why they had to switch.
Still, I wonder why it took so long for them to make up their mind on the face and why they didn't get it right the first time.
I honestly can’t tell the differences and think the lighting and emotion is what makes these screenshots look different. The model and textures seem pretty much the same. There’s a chance the blendshapes used for certain poses go off model or make the textures look different as they swim or pull with the geometry but to me it looks the least like TNG Jelico when certain expressions are used which are out of character for him rather than a different face itself.
Knowing how productions run as well, usually assets are approved before they are used in any episodes. Things do change slightly for performance reasons to make a character achieve certain things needed in the script but the model designs are usually approved well in advance of animation. Changing models in production is costly and usually problematic. There’s a chance maybe that you could make changes between seasons but it would be rare as seasons are in production back to back.
Note: In a few of these, I have multiple images of what I consider to be the main variants, which I would say are S1 E15 version, S1 E19 version, S2 E5/E9 version, and S2 E14 onward.