Manboy,when you set your NP up the first time you are trying to get a consistent anchor,consistent grip etc.Adjust your NP with the site level the first time and you wont have to worry about it.
If you are canting the bow either direction,yes the NP will tell ya that,meaning you dont have a proper grip on the bow from what you set it up to.Make sure its perfect and comfortable to YOU and everything else will just fall into place.
When you draw back to full anchor,grip is perfect the little black dot will be dead centre in the yellow circle,
Hope this helped answer your question