Address late review comments on image entity URL support (#95338)

homeassistant/components/image/__init__.py

@@ -167,10 +167,7 @@ class ImageEntity(Entity):
         """Return bytes of image."""
         raise NotImplementedError()
 
-    async def async_image(self) -> bytes | None:
+    async def _async_load_image_from_url(self, url: str) -> Image | None:
-        """Return bytes of image."""
-
-        async def _async_load_image_from_url(url: str) -> Image | None:
         """Load an image by url."""
         try:
             response = await self._client.get(
@@ -193,10 +190,13 @@ class ImageEntity(Entity):
             )
             return None
 
+    async def async_image(self) -> bytes | None:
+        """Return bytes of image."""
+
         if self._cached_image:
             return self._cached_image.content
         if (url := self.image_url) is not UNDEFINED:
-            if not url or (image := await _async_load_image_from_url(url)) is None:
+            if not url or (image := await self._async_load_image_from_url(url)) is None:
                 return None
             self._cached_image = image
             self._attr_content_type = image.content_type