(I work on Grok) We've been working on teaching the model how to reason about great visual design principles. Obviously this is hard and somewhat subjective, but through a combination of writing down these principles (e.g. how to think about systems, not just "use this italic serif font on marketing pages"), and then creating a lot of data to pairwise compare designs/outputs, we've made a notable improvement over G4.5 and see a path to improving much further in the next model.