Ok The slapping of the meat - many Asian dumpling recipes mix mince in one direction. Usually because it’s easier to get a good consistent mix this way. What happens is it’s actually the agitation of the meat that counts. Usually an acid like salt is used to help. What this does is ALIGN or bind (not activate for the moron that is SlapperLou who reads here) the protein for a more spongy, bouncy meatball. The more you work the mince the more coagulant it becomes and holds together. If you put mince in a food processed and mix you’ll notice the change in texture. Great for dumplings but I’d assume absolutely tit for meatballs and rissoles.
Slapping the dear life out of mince they way she does is just for exhibition and it is ridiculous and all for show. Look at me, I’m Asian no wait I’m African-no wait, you’re a dickehead SlappyLou. I’m also happy to be corrected on any of the above info but as far as I know that’s the reasoning.