Update app.py

app.py

@@ -148,7 +148,7 @@ def enhance_prompt_with_gemini(prompt: str, style: str) -> str:
 
 def generate_marketing_image(prompt: str, style: str = "realistic") -> str:
     """
-    Generate a professional marketing image using Google Imagen3.
+    Generate a professional marketing image using Google Imagen4.
     
     Args:
         prompt (str): Description of the marketing image to generate