He's looking at the grid to either ensure it matches the putting grid, and if not (I assume) he's taking the pitch/chip grid as the correct one.
Give it a whirl.
Play a round and look at the pitch grid, compare to putting and make a mental note when the two are showing different breaks, then putt and see which grid it follows.
I also use the pitch and chip grids on those funny breaks where both sides of the hole ball runs into the hole, or away....in those cases I play the pitch/chip grid....and hope;)