Reading the title I expected to see something outrageous. What I saw was nothing out of the ordinary. Anyone outside of the JW religion or not having any experience with it would think this post to be quite strange. However being raised in it and knowing that his dancing, though poorly, is nothing to get worked over, but would be condemn by most elders. In fact there has been countless articles and special talks on this sort of activity.
Overall this video will have little impact on most witnesses or non-witnesses as it comes across as harmless. If he was grinding her or other dancing then it would be different.