I appreciate the video, and the effort that you made to help people out, but without close up shots of the grain, viewers can't really see the difference at all. Personally, I was excited to see the comparison as well, but could not see any fine details. 😅
This is a method of Pre raising the grain and then sanding it smooth before applying the water borne finish. If you simply apply the finish without "raising and sanding the grain" first, your finish will raise the grain and now you'll have to sand it smooth and reapply the finish. Good trick and it saves you money on stain since you'll be using half as much.