My only real point was like... yeah, some box prototypes might work for some developers, that's cool if it does. But for me it usually doesn't. (depends a lot on the type of game, really)
I prefer to have -some- kind of art in there, so the art has a chance to evolve along with the gameplay. I also put in music and as much other stuff as I can to get more of a feel for things. The music influences the gameplay, the gameplay influences the story, and vice-versa. Essentially, for me, all elements of a concept are interconnected and I feel weird separating them.
Now, in some cases, its necessary to look at one piece at a time, and that's fine. But in my mind its still interconnected.
I know some other devs are cool with prototyping game play by itself and finding a musician to write music for it later as a completely separate process, etc. That's totally valid, its just not
my approach. You end up with a different type of final result. I'm not saying its better or worse, its just kinda different!