" An AI shown a sheep with polka dots or tractors painted on its sides will report seeing the sheep but will not report anything unusual about it. When you show it a sheep-shaped chair with two heads, or a sheep with too many legs, or with too many eyes, the algorithm will also merely report a sheep. Why are AIs so oblivious to these monstrosities? Sometimes it’s because they don’t have a way to express them. Some AIs can only answer by outputting a category name—like “sheep”—and aren’t given an option for expressing that yes, it is a sheep, but something is very, very wrong. "

― Janelle Shane , You Look Like a Thing and I Love You: How Artificial Intelligence Works and Why It's Making the World a Weirder Place