Because the icons were visually appealing, making them more interesting to people
In his old age he became a communist and during the cold war it was just too tough to be a communist in the US. He went to Ghana after it became the first African country. DuBios has worked for African independence all his life, and was invited to enjoy it by Kwame Nkrumah, his old friend, and Ghana's first president.
The territories of Poland was known to have expanded as agreed on the Treaty of Versailles right after the first world war. Germany looses most of its territories at that time and some of it were given to the Polish. Poland acquired these German territories: West Prussia, Posen and Upper Silesia.