1. This is a VLM, not a text-to-image model. You can give it images, and it can understand them. It doesn't generate images back.
2. It seems like Pixtral 12B benchmarks significantly below Qwen2-VL-7B [1], so if you want the best local model for understanding images, probably use Qwen2. If you want a large open-source model, Qwen2-VL-72B is most likely the best option.