Very simply, the principle(s) being used. This is the difference between that which you watch when trying to work out what the differences are. The principles being used and if indeed the very same principles are being used in the two videos you choose then how they are being used would then be the difference.
Are we speaking of the principles of ma'ai and kuzushi as mentioned earlier or different principles? Sorry Graham I'm not always on your wave length, I appreciate your patience with me.