Maybe he's not happy with something or expressing disagreement.
Maybe it's expressing disagreement or showing that it's confused.
Maybe it's expressing disagreement or showing that it doesn't like something.
Maybe he's not happy with something or doesn't agree with what's going on.
The man might be shaking a bottle or a rattle.
Maybe he saw something he really didn't like or thought was bad.
Maybe he didn't get what he wanted or expected.
It could be that the character doesn't like the idea or situation presented. Or perhaps it's responding negatively to a request or suggestion.
A cartoon man shaking hands could be because he's meeting someone new and wants to be polite, or it could be part of a story where he's celebrating a successful collaboration. There are many possible explanations.
You can start by sketching a simple oval for the head. Then, draw two lines for the neck. For the shaking motion, show one side of the face slightly tilted and the eyes looking in that direction.
First, draw the basic shape of the head. Next, make the hair flowing in the direction opposite to the shake. For the face, use simple lines to show surprise or frustration. It's not that hard once you get the hang of it.