"Ah, how cute. The nice fat sow is nursing the even cuter little piglets in blissful loving motherhood.
All soon to be slaughtered."
Well, pictures do say more than a thousand words. And that offers a multitude of interpretations.
As this question is framed and the original source misses to give necessary context:
Almost all schoolbooks do that. In America they include intelligent design in biology textbooks. In many countries they have a famous picture in them that is incredibly brutal: a small boy with fear in his face and his hands up is rounded up by German soldiers and on his way to death in a concentration camp.
Then many caricatures are frequently used to teach the children how to analyse them.
In this case, perhaps: Describe the picture, analyse what is used to convey a message. What is this message? Is it true, or manipulative? –– Then I would say: "nicely done."
It can be really 'just an illustration' used to spice up a bland text about the inner workings of the EU financial politics of specific time. If used in this way to summarise the textual content, I'd say: "What were they thinking?"
All schoolbooks have political content, politicised content in them. Some have disgusting content or questionable content. Some may have content you disagree with.
It is a matter of context, aim and presentation.
This can be seen as necessary to teach the school children how the politicised world of mass communication works. This can be used to indoctrinate the students in certain ways. Politicised content can be good, can be egregious. But it cannot be seen as avoidable. That would make a lot of books useless. Especially those about history, sociology and other social sciences close to politics itself. Thinking of it as 'avoidable' is an illusion. And necessarily a backfiring one.
Notice that in this case the picture is the following:
And the text seems to say:
Among the world's leading powers.
Of most of the people who are living in Europe, most of them are farmers. It is one of the most important policies of the European Union, the dominant role of the world economy and the world of politics.
Does anyone get it? Germans pay the most into the European Union's coffers. Identify the cartoonists, then elaborate the picture.
(Mostly machine translated. And therefore dubious in its intricacies.
Hungarian speakers: Please correct if this is incorrect.
The translation is preliminary.
Do not read too much into the English version of it!)
Notice the imperfect depiction of one piglet. It's either Belgium done wrong or again Germany! A pertuum piglet.
If the translation approximates correctness, I'd say that this leaves most of the outcome to the teacher, as there seems to be no obvious solution given? Can be good, can be bad.