That's a special 'see where you are retreating too' sight. Actually, in fairness it might have been done on purpose for some unknown reason such as framing, or perhaps for a contest where you 'spot the deliberate error'. Note too, that he is holding the MG left-handed, presumably to show off the feed belt, we know he is in fact right handed.
does the way you mount it actually matter (it's an actual question - I'm curious)? I tought they where designed like that to give more flexibility and have once mounted it backwards to fit a certain (tight) setup.
What disturbed me was him standing there waving the MG for no purpose thru the whole vid ^^
Plenty of reasons for him to make vids, not least of which is to promote the business, and of course to wish people season's greetings. I don't see why people object to him so much tbh, yeah he bigs up mediocre products a little, but all shops do that, and after all is said and done, nobody is forced to buy stuff off him.