"ego cogito, ergo sum" by Antje Wenner-Braun is a square poster available in sizes 50x50 and 100x100. The poster features a thought-provoking photograph of a thinking gorilla. The brown and black tones highlight the natural beauty of the animal, capturing the essence of animals and nature through photography. It is a captivating piece that stimulates contemplation on the complexities of the mind and existence.