Here's what ChatGPT had to say about it:
The cartoon humorously plays on the classic character Don Quixote, from the novel by Miguel de Cervantes. In the story, Don Quixote famously mistakes windmills for giants and attempts to fight them.
In this cartoon, Don Quixote is depicted on his horse with his lance, but instead of a windmill, he encounters a simple electric fan. The punchline, "I will not fight a child," adds to the humor by suggesting that Don Quixote perceives the fan as a much smaller and less threatening opponent, akin to a child, thus deciding it's not worth fighting. The absurdity of mistaking an electric fan for a child, combined with the reference to his original confusion with windmills, creates a humorous twist.
because it's a small fan, this hinges on the premise that a windmill is a big fan.
You see, the comic doesn't denote who is speaking. So I am asking as if I think the fan is the one speaking to the old man. Thus making a secondary, arguably worse, joke.
Fan sized windmills, definitely. It's just tiny structures. I could kick them. Or push them over. Carry them away. A windmill sized fan on the other hand is fucking scary.
Yeah I realized when I posted, this is a no brainer. Also I’m guessing most people pick the duck sized horses as well.
It's not a political comic.
Don Quixote (fictional character from the book of the same name) mistook windmills for Giants and tried to fight them.
So he's mistaking the small fan for a child, in the same way as the windmills.