Replace gallery with single image output

Simplify the UI by showing one generated image at a time instead of
accumulating images in a gallery. This removes unnecessary state
management and makes the interface cleaner.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

app.py

@@ -365,7 +365,7 @@ def prompt_enhance(prompt, enable_enhance):
 
 @spaces.GPU
 def generate(
-    prompt, resolution="1024x1024 ( 1:1 )", seed=42, steps=9, shift=3.0, random_seed=True, gallery_images=None, enhance=False, progress=gr.Progress(track_tqdm=True)
+    prompt, resolution="1024x1024 ( 1:1 )", seed=42, steps=9, shift=3.0, random_seed=True, enhance=False, progress=gr.Progress(track_tqdm=True)
 ):
     """
     Generate an image using the Z-Image model based on the provided prompt and settings.
@@ -381,13 +381,12 @@ def generate(
         steps (int): Number of inference steps for the diffusion process
         shift (float): Time shift parameter for the flow matching scheduler
         random_seed (bool): Whether to generate a new random seed, if True will ignore the seed input
-        gallery_images (list): List of previously generated images to append to (only needed for the Gradio UI)
         enhance (bool): This was Whether to enhance the prompt (DISABLED! Do not use)
         progress (gr.Progress): Gradio progress tracker for displaying generation progress (only needed for the Gradio UI)
 
     Returns:
-        tuple: (gallery_images, seed_str, seed_int)
-            - gallery_images: Updated list of generated images including the new image
+        tuple: (image, seed_str, seed_int)
+            - image: The generated image
             - seed_str: String representation of the seed used for generation
             - seed_int: Integer representation of the seed used for generation
     """
@@ -420,11 +419,7 @@ def generate(
         shift=shift,
     )
 
-    if gallery_images is None:
-        gallery_images = []
-    gallery_images.append(image)
-
-    return gallery_images, str(new_seed), int(new_seed)
+    return image, str(new_seed), int(new_seed)
 
 
 init_app()
@@ -479,8 +474,8 @@ with gr.Blocks(title="Z-Image Demo") as demo:
             gr.Examples(examples=EXAMPLE_PROMPTS, inputs=prompt_input, label=None)
 
         with gr.Column(scale=1):
-            output_gallery = gr.Gallery(
-                label="Generated Images", columns=2, rows=2, height=600, object_fit="contain", format="png", interactive=False
+            output_image = gr.Image(
+                label="Generated Image", height=600, format="png", interactive=False
             )
             used_seed = gr.Textbox(label="Seed Used", interactive=False)
 
@@ -502,8 +497,8 @@ with gr.Blocks(title="Z-Image Demo") as demo:
 
     generate_btn.click(
         generate,
-        inputs=[prompt_input, resolution, seed, steps, shift, random_seed, output_gallery],
-        outputs=[output_gallery, used_seed, seed],
+        inputs=[prompt_input, resolution, seed, steps, shift, random_seed],
+        outputs=[output_image, used_seed, seed],
         api_visibility="public",
     )