These are some great examples of cartoony drawings in their purest forms.
Otto Messmer is probably the biggest influence on American animation there ever was.
His drawings are boiled down to the very essence of what a cartoon is. He's not even trying to mimic reality. His style is very simple, but also appealing.
Even his props are fun to look at. This quality of being fun to look at is what makes a cartoon different than other forms of illustration.
The simple shapes and symbolic stylized expressions Messmer uses tell the viewer clearly what is happening and what the character is feeling.
Messmer's style owes a lot to early cartoony comic strips like The Katzenjammer Kids, but also reveals graphic innovations that he discovered through trial and error by having to move characters about on screen.
Poses that are moving have to be even more clearly staged than still drawings in a comic strip, because in film, we only have a limited time to look at each pose before it moves into another.
Animators like Messmer and most who followed him quickly learned that clear negative shapes and using only a few lines and details helped make characters communicate faster and more clearly when animated. It also made them easier to animate, which resulted in better movement.
By turning the practical realities of animation into graphic appeal, he solved a lot of problems for the rest of us.