The process is clear enough for anyone to see, and yes, Jay has cleverly identified the dressing stone for what it is. This method is easy and painless which means it gets done in a timely way and not put off excessively. Sometimes I dress and in the case of a particularly brutal grinding dress again immediately afterwords before another go at it, that's just the way it is though your results may differ depending on the stone in front of you. I will just add that I've worked with only three depth indicators, perimeter and central but prefer going with 5 - maximum allowed - as in the case presented.