Update app.py

app.py

@@ -446,7 +446,14 @@ def choose_caption(input_image):
             "role": "user",
             "content": [
                 {"type": "image", "image": image},
-                {"type": "text",  "text": "Please describe this image in **very** **short** caption."},
+                {
+                    "type": "text",
+                    "text": (
+                        "Describe this image in one sentence, starting with the main object, "
+                        "then its key features, followed by the background elements. "
+                        "Use a clear, concise style, e.g., 'a photo of a plastic bottle on some sand, beach background, sky background'."
+                    ),
+                },
             ],
         }
     ]