It's a huge difference, not only power wise but also punches getting threw the guard.
If you covered up like that with mma gloves you'd be separated from your consciousness for it. It also makes it hard to see what's coming, but it's only a left or right hand in boxing so you can get away with it more.
If they would allow one of these minor changes either mma gloves, leg kicks, or clinching/dirty boxing it would completely change the outcome.
I think Mcgregor is going to do better than people think. I'm curious to see the distance he keeps, if he switches back and forth south paw/orthodox, and his hand positioning. In mma your hands are usually held lower to defend take downs and catch kicks. I'm curious to see how it plays out, not curious enough to pay for it though.
I'm not a huge fan of either guy but I'm hoping McGregor pulls it off some how. I can't cheer for a guy that beats up women in front of his kids.