Texturing is a way to add details using Normal, Bump or displacement. No modeling, and it looks perfect.
But Texturing is also a way to opacify some modeled parts.
Using both techniques, it is possible to change a primary design and make another one.
To explain a little bit more, just look at the pictures below. These are Iray rendering. The original Toon School Bus is modified to give the special Bus at the right.
Take a minute and try to check what has disappeared in this picture :
And now, what details is new?
This is magic, the model doesn't change but well the texture.
And what about another toon Bus? Just check below one of the Iray Texture I'm working on :