Image-to-image is a different contract from text-to-image. Instead of asking a model to invent a scene, you hand it pixels you already approved and ask for a change inside them. Google’s own wording for this mode is narrow and specific: provide an image and use text prompts to add, remove or modify elements, change the style, or adjust the color grading. That list is short on purpose. Framing, perspective and the subject’s placement are meant to survive the edit.
The practical consequence is that the source image carries most of the art direction. You do not re-describe the lighting you already shot, the wardrobe you already styled, or the logo placement you already approved. You describe the delta. This is why the same workflow that retouches a product packshot also handles seasonal variants, background swaps for regional campaigns, and style transfers where the original composition has to be recognisable afterwards.
This workbench runs three Nano Banana tiers from Google. The tier is a choice you make in the panel, not something the system assigns, so the difference between a 5-image reference ceiling and a 14-image one stays visible while you work. Image-to-image and text-to-image share one entry point and one credit balance, which means a draft generated from a description can be edited in the next step without moving to another tool.