The above case is not about inciting violence or terrorism. Let me cite a bit of the official court press release about the conviction* (google translate, with small corrections):
"The district court writes in the judgment that those who exercise their freedom of expression - in the picture, voice or text - also have a duty to the extent possible, to avoid statements that are unjustifiably offensive to others and statements that do not contribute to any form of public debate. The judgment is that Dan Parks and gallery owner aim of the exhibition have not been to bring an informed debate, but rather to provoke. On the way they spread the pictures, they have not taken responsibility. Protection of the individual to avoid insults and slurs are therefore in this case of higher priority than freedom of expression and the right to freedom of art."