Google’s 23 September 2026 Flow Tools announcement included ThumbnailForge, which combines an image, headline and prompt into cover artwork. It is a 27-day-old example, not this week’s launch. It raises a useful question for a series of covers: how do you change the setting without changing the character? The checks below apply to editing in Gemini; they do not certify that a separate Flow tool keeps identity perfectly.
You ask for a different background and receive a different character as well. A revision can drift beyond the requested change. Make the reference and the fixed details explicit rather than relying on “keep everything else”.
Use the approved image
For a fictional orange fox wearing a blue scarf, keep the original file. State that face shape, fur markings, scarf colour and pose should remain while the background changes from autumn to winter. Describe the change and the invariants in separate sentences.
Gemini’s current help lists Nano Banana 2 for image editing, including uploaded images and multiple references. Editing requires age 18+ and a supported app language and country; managed accounts can have different terms. The Lite variant is not designed for multiple references or repeated edits. Check the selected model and actual account access before starting.
Inspect the unchanged areas
Compare the face, clothing, silhouette and framing before judging the new background. If the scarf became green, identify that specific failure. Try a targeted correction with the approved reference instead of repeatedly editing a version that has already drifted.
Keep a version you can return to
Save the original, accepted edit and any later variants separately. Check the final downloaded dimensions and format. Use only references you are entitled to share. For an actual person's photograph, obtain the necessary permission and avoid using a generated edit as evidence that an event really happened.