To me emergent phenomena are things that simply can't be analyzed just looking at the building blocks the emergence comes from. Say, a photo of a cat is made of pixels, but there is no meaningful way to discuss "catness" of a single pixel. The RGB value of a single pixel simply has no information in that that distinguishes a non-cat pixel from cat-pixel. Only when you take a pile of pixels you may start to dicuss if that pile contains a cat or not. But you need to falsifiably define the catness of the image by something else than RGB values of individual pixels.