Update README.md

Author: RobertFlatt

README.md

@@ -167,7 +167,11 @@ Optional arguments:
 Specify which camera to connect to. For example `camera_id = 'front'`. A string containing an integer (default '0'), or on Android 'back' (default), or 'front'.
 
 ##### mirrored
-Boolean default `True`. Mirrors the preview image. Ignored on Android where by convention 'front' is always mirrored and 'back' is never mirrored. Captures are never mirrored, except a screenshot capture if the Preview is mirrored.
+Mirrors the Preview image, default is `True`. This option is ignored on Android where by convention 'front' is always mirrored and 'back' is never mirrored. This option should usually be `True` for any camera facing the user, and `False` for any camera not facing the user. 
+
+Captures are never mirrored, except a screenshot capture if the Preview is mirrored.
+
+The pixels argument to `image_analysis_callback()` is never mirrored, if a Preview is mirrored a `texture` result of any image analysis will be automatically mirrored in the `canvas_instructions_callback()` by the tex_size and tex_pos arguments. If image analysis genetates image annotation locations, these locations must be adjusted by the app for a mirrored preview. See the [Image Analysis Section](https://github.com/Android-for-Python/camera4kivy#image-analysis) for code fragmets and links to examples.  
 
 ##### filepath_callback
 On a capture of a photo, video, or screenshot, this argument specifies a method to receive the path and name of the saved file. For example `filepath_callback = my_method`, where `def my_method(self, path):` is an app supplied method with a string argument.