Gemini 2.5 Flash Image: Nano Banana’s Breakthrough in AI Character Consistency

For years, creators using AI image generators have faced the same headache: characters don’t stay consistent. A face might subtly shift between prompts, hairstyles change, or clothing designs vanish altogether. What should be a single character across a story often turns into a cast of near-strangers, making it nearly impossible to craft coherent narratives, marketing campaigns, or even simple visual series. The dream of a consistent, AI-generated story felt forever out of reach. It’s not just the problem of Stable Diffusion, Midjourney, Adobe Firefly, but almost all AI image generators. 

The launch of Nano Banana, the codename for Gemini 2.5 Flash Image, really marks a milestone. Not stopping at a normal upgrade, it represents a huge shift, a step forward from generating static images to creating persistent, recognizable characters. It promises to deliver on what creators have longed for: the ability to generate a character and keep them consistent across an entire series of images. 

The Old and Painful Workflow of Image Generation 

Before Nano Banana, working with Au characters was less of an artistic collaboration and more of a technical wrestling match. The core issue lay in how earlier models processed the prompt. Each new prompt was treated as a completely new request, a blank slate. The AI had no “memory” of the previous images or characters. It would generate the new image based on the prompt’s token list, not based on the visual identity it had created just moments before. 

This led to an issue we can call “character entropy”. With each successive prompt, the character’s unique features would decay, replaced by a new, but similar, set of features, such as the curve of their jaw, the hairstyles, or the nuances of their expression. Creators were forced into a painful workflow of generating a lot of images and then selecting the few that were “close enough” before resorting to manual fixes. This often meant using specialized software to perform workarounds like “in-painting” to repair inconsistent features or running complicated “ControlNet” pipelines to force some consistency. The process was more about technical manipulation than creative flow.

For a better explanation, here is what artists and storytellers had to do: 

• Draft characters repeatedly because most models failed to recall a face or style from prompt to prompt. 

• Rely on long, rigid prompts, repeating every detail, “short brown hair, oval glasses, green jacket, soft lighting”, only to receive variations that drifted off-model. 

• Use image-to-image workflows, which helped but locked creators into narrow compositions and limited experimentation. 

• Manually edit results in Photoshop or similar tools to fix inconsistencies—a time sink that undermines the speed advantage of AI generation. 

For instance, in our previous project of a Manga Generation tool, when asking a model to generate “a photo of a girl and a boy playing in the forest”, each time it generated a different image with different characters. This was a huge challenge for the team. 

How Nano Banana Works 

Nano Banana currently seems outperforming other image generation models, even Kontext, GPT Image 1, or Qwen, in terms of Confidence intervals on model strength, fraction of model A wins for all non-tied A vs. B battles, and Average win rate against all other models.

Instead of treating each new prompt as a blank slate, Nano Banana operates with a persistent “character identity” model. When you generate a character, the AI doesn’t just create a one-off image; it develops a latent vector representation of that character’s core features. This vector acts like a digital fingerprint, a non-degradable identity that the model can recall and apply to subsequent images. 

The key features that enable this revolutionary consistency are: 

• Identity anchoring: The model is specifically trained to recognize and lock onto a character’s defining features, including facial structure, hairstyle, and even unique accessories. This goes beyond simple token recognition; it’s a deeper understanding of visual continuity. You can now use a text prompt like “The woman with the red scarf,” the AI will recall the exact scarf from previous images. 

• Contextual intelligence: Unlike earlier models, Nano Banana extends to more than just the character. It understands how the character should look in different contexts. This means it can apply the same character model to new scenarios, adjusting their pose, clothing, and even shadows to match the new environment, all while keeping their identity intact. 

• Integrated multi-turn editing: The model’s strength lies in its ability to handle multi-turn conversations. You can upload an image of a person and then ask it to “change their jacket to leather,” “place them in a forest,” or “make them smile.” The AI will perform these edits while preserving the core identity of the person in the original image, making it an incredibly powerful editing tool. 

Practical Applications of Nano Banana 

The impact of Gemini 2.5 Flash Image goes beyond a simple fix for a creative problem. It opens a new era of possibilities for various industries. 

Comic book artists can now rapidly storyboard entire narratives with the same character, greatly accelerating their workflow from weeks to hours. Novelists can produce character sheets or scene illustrations consistent and true to their vision. 

On top of that, brands can now create a consistent visual identity for a mascot or spokesperson across the countless ad campaigns, social media posts, and product photos without the expense of multiple photo shoots. 

What’s more, designers are able to generate 3D models of a product and then use Nano Banana to place it in different environments, a coffee shop, a clean studio, or an office, all with perfect consistency, providing a powerful tool for visual marketing and prototyping. 

Looking Ahead The Future of Image Generation 

Gemini 2. Flash Image Nano Banana moves the technology from a tool for isolated image creation to a platform for true narrative and brand building. Since it solves the most frustrating problem in AI art, it has unlocked the full potential as a collaborator for storytellers, designers, and marketers. And Nano Banana has proven that we are finally on our way.