Nucleus-Image is a text-to-image model built around sparse mixture-of-experts routing. In plain terms, it has a large set of expert blocks, but each generation step only uses the parts it needs instead of running the whole network every time.
That matters if you care about the tradeoff between image quality and inference cost. You still write a normal prompt and get an image back, but the model is designed around using less active compute than a dense model of the same total size.
For example, you can prompt for a product mockup, character portrait, poster-style visual, architectural scene, or wide cinematic frame, then choose one of the supported aspect ratios instead of being locked into a square image.