Both work, which is why a lot of Japanese readers have long been confused as to whose line that was exactly: Netero's or the King's? The animated adaptation has finally clarified that.
The fact remains that the line says "you were in checkmate from the beginning", so the English translation messed up.
The manga translates it a bunch of different ways. Regardless, it makes sense whatever way you put it. Both of them were in checkmate.
Not referring to the pose, it's referring to the fact that in the game, Netero said he won't be using his left arm or right leg.
Of course it wasn't planned over more than a decade obviously, but it just has to be a reference.
Damn, son, I never even noticed that. Shit's over the top cray. Togashi GOAT storyteller.
That was me and I made sure it was said prior to this episode. And it's not like his name is a huge revelation that changes the way you think about him. It's a made up name like Pitou and the others and have no meaning behind them.
Actually, the name Meruem does mean "the light that shines over all" (according to the queen). But it still doesn't affect the story.
Edit: Also, all the Royal Guards names are references to Egyptian Gods combined with the names of characters from some french book, and Meruem comes from something in arabic. (Bonus points to Pitou's abilities Dr. Blythe and Terpsichora which are also references to the Blythe doll and a Greek Muse respectively)
