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.