“what does it mean if the point is red???? “
I believe that is indicating that this step corresponds to an image which highlights a specific step. I saw this two times, in step 4 and step 9. For step 4, it shows the highlight in the second image and for step 9, the highlight is in the first image. It seems that the red bullet point is just to make it easier to map the step to the image.
Hope this helps