Well, I think you should look at why cartoons look the way they do (and by the way animation can look lots of different ways). At it’s most basic level animation is a film made one frame at a time. Because this means each frame is finished with much greater effort than it would take to film live action this often means the rendering of an individual frame must condense the amount of information in a given frame. But this isn’t the only reason cartoons look the way they do. If the look of animation was simply a consequence of limitations imposed by its production there would be no reason to make animation at all. After all, who wants to work harder to make something when it could be done easier in another way? Obviously they don’t. People choose to animate rather than film live action because they don’t want their film to be bound by visual realism. Unless your name is Zemekis.
As such in a cartoon world live action would look like whatever style of animation the world would look like to us. They would no more animate films to look just like the world they live in than we would—that is to say, one nutter would and everyone else would natter on about how pointless and creepy-looking it was and that he should have just filmed it. So if there were animation in this cartoonish universe it should look just as different and varied as our own animation does. In a nutshell It will be as varied from abstraction to realism as their imaginations allowed.