That test is misleading. You have to watch very closely to be sure the stylus is skating on the vinyl and not following the groove. In your video it is clearly in the lead-out groove. Some test records have a blank side for this. Best is a 45 LP cut on one side only, leaving the other completely blank.
All this side bias testing seems to me is missing the point. Because if the problem was side bias you would be hearing it from one speaker or the other, or more in one than the other. Like Mike said, right is outside groove wall away from the spindle, left is inside closer. If you are hearing it equally from both channels (or close enough you can't tell) then your side bias (anti-skate) is correct and it is something else.