the reason for the two bar system is so it can tell you how confident it is in reading the image you are presenting, and then whether the image matches your model. With strange angles and lighting the software uses the first bar to show you how well it can read your image. Then, based off of how well that image is read, it gives a second bar to show whether or not it is a match. If you have a low first bar but a high second bar, you may need a better source image because lighting or other factors could be throwing it off.