Throughout the movie Vitani's design always seems to be different. Here are all the modifications/differences between her appearances.
Vitani's design remains consistant when she is a cub. No dark ear mark are present and the sides of her face are pointed. She also has no whisker markings, her eyes are a very distinctive blue and her "eye-brows" are slim.
Adult design 1
The most common design of Vitani as an adult. The most noticable change is her ears. She now as dark ear marks. Other new features is her whisker marks and rather rough "eye-brows". The final difference between this and her cub design is the sides of her face, they're now rounded instead of pointed.
Adult design 2
The second most common adult design of Vitani. Everything remains the same as the previous design except for her ears. They're now back to her cubby ears, no dark marks. This design probably isn't a alternate design at all. It looks more like a frequent colour blooper. The lines for where her dark ear marks should be are still visible, suggesting that the ink & paint artist/s may have been referencing the cub vitani model sheet or something. On a final note I personally believe Vitani's eyes appear red in this scene due to the hazy atmostphere of the Elephant Graveyard.
Adult design 3
Once again, no dark ear markings for Vitani. The only other difference in this picture is the sides of her face. They're pointed, just like in her cub design. Probably just a "mistake" (even though they look better pointed in my opinion.)