How does the arcoreimg Tool calculates the score?

Im using the arcoreimg Tool from ARCore for the first time for a Project and with the

arcoreimg.exe eval-img --input_image_path=dog.png

command I calculated the img score of numerous pictures, but i still have no Idea how this tool calculates the score. I played around with different coloring, contrasts, backgrounds and dont get a consistent result. Which conditions, features are important in a picture to get a high score?

Google manages that utility, you may find better support on the ARCore SDK page on Github GitHub - google-ar/arcore-android-sdk: ARCore SDK for Android Studio