The term "artist" here is being used kind of loosely. They're doing the bare minimum you need to turn a skeleton into a living creature. Good artistic representations require a lot more imagination, beyond what we scientifically know. You can get clues by looking at already existing animals and how they relate to their skeletons. Which gives an idea of how much not bone material those creatures might have. No you won't know exactly how much they did, but that's not really being represented by skin wrapping either is it. Better to try and go for something believable rather than the bare minimum.
