The image is a page from a book, likely a dictionary or phrasebook, containing Turkish insults and their French translations. The words in Turkish are presented with their IPA (International Phonetic Alphabet) pronunciations in square brackets and French equivalents. There are also simple illustrations accompanying some entries. The joke, or rather the dark humor, lies in the sheer vulgarity and offensiveness of the Turkish insults. The book is showing the range of insults available in Turkish, and their corresponding French translations, showcasing the cultural differences in expressing such strong negative emotions. There's no single, easily explained "joke" – it's an illustration of harsh language. In short, there isn't a joke in the conventional sense. It's a compilation of offensive language and its translation.
Anlaşılan Fransızca bildiğin kadar Türkçe de biliyorsun 😅