I guess if you were using what comics illustrators refer to as standard human dimensions, you might have a point. In my opinion, the level of exaggeration in the length fo her torso is not out of line with many, many comics characters, artist styles, etc.
The added leg is drastically too short, my friend.
Look, I'm a retired art director. I worked at the national and international level in high end t-shirt design, separation and printing for more than 20 years before retiring due to health reasons in 2009. I was either the art director, creative director, or operations manager at companies ranging in size from two million dollars gross annual income up to forty five million dollars gross income. I've had as many as 9 artists working under my direction, with 5 of those being purely creative and the other four being what we called production artists, or in other words; artists proficient in the technical side of preparing art for screen printing.
Anways, from my perspective, what happened here is obvious. The client, or kitten's director, requested the change in the design very late in the process, possibly at the very last moment before the piece was due to go to print. By the time the request was made, kitten had done sufficient work on the image that going back to pencils was out of the question. As she began making the change, she started with almost no time left to get it done, and no practical way to sketch or draw the leg in layout form in order to work out the proper dimensions.
Considering what I know of kitten... knowing what a pro she is and the experience she has, I have no doubt she told whomever ordered the change that it was a bad idea. My guess is she was not happy at all to have to make this kind of edit to the image at the last minute.
Having no choice, she added a layer, and began to manually add in the leg in Photoshop. She had perhaps a single day (maybe even less than that) to execute the change. When it was done, both she and the director, or client, knew the leg was wrong, but were out of time if they were going to meet the deadline.
That leg is clearly, without doubt, about half as long as it should be to be in proportion with the rest of her body.
By the way, I mention my experience not because I think my opinion is better, or more significant than yours. I told you about my experience as an artist/art director only to demonstrate my point of view regarding this image. I saw this kind of thing all the time in my career, both in my own work, and in the work of my artists. There is only so much you can do when you are down to the wire and under the gun.
If I am right, and the scenario played out something like I suggest here, I give kitten high marks for pulling off the change as well as she did. Both myself, and my artists used to hate this kind of change to what was going to be a really sharp piece of art, with a purple passion.