If one really does want to find a nigger in Poland, one is for sure going to find one, but niggers are rather rare species in the eastern Europe, including Poland.
I believe, those woke artists sometimes place some sorts of shitskins just to create a controversy. Honestly, even in my country I do not remember what commercials stores used to run, but I remember a particular one where they placed a nigger (actually a nigger-model from abroad) as it caused uproar, people were sending negative messages to the particular chain featured in the commercial and newspapers were publishing articles about lingering racism in the population because of those messages.