This cartoon, set on a fictional planet, is about the earthly debate about the return of cultural artefacts in museums to the nations from which they came. Sometimes such objects have been plundered, sometimes obtained due to the leverage of dominance, and sometimes obtained fairly.
The point that the cartoon is trying to make is that such transactions are rarely as simple as they are portrayed, with one dominant nation or empire invading another land and plundering its cultural wealth. The parameters of this scenario are set too narrowly.
In many cases the less dominant nation was previously a colonising or imperial force itself, which may have been how it came to be rich enough to produce cultural artifacts of value.
On my fictional planet for example, the nation that produced the gold artefact had plundered the gold from which it made the object from a country that it had subjugated.
It can be argued that sophisticated cultures cannot evolve without the dynamic of conquest.