I don't have reliable information about a self-portrait or artwork titled "Auguste-Nicolas Caïn" by Auguste-Nicolas Caïn in my training data. Auguste-Nicolas Caïn (1821-1894) was a renowned French animalier sculptor celebrated for his dynamic bronze animal sculptures, but I cannot provide specific factual details about this particular work without risking inaccuracy. If you could provide additional context such as the date of creation or current location, I would be better able to assist you.