I can explain the concept for you:
The reversed thing is the in-game Bosse is not just a "Boss" in the script anymore. Like, Mayo Nugget, Wise Ape, they starts to think that: Why I should stay here and be defeated by those "Players"? I can be the "Player" in this world too! They all strive to break free from the constraints of game code, creating bugs (beating other bosses etc.) in search of their own freedom (which is what players in front of the screen doing).
The perspective has reversed, and we are now thinking from the perspective of the in-game Boss（looking for freedom etc.）