How to interpret BGA package for creating footprint
Draftspeople at 90&deg; angles

The draftsperson who drew the pin map drawing drew it rotated 90&deg; from the draftsperson who drew the package drawing.  Rotating it 90&deg; clockwise makes the index pin (A1) match up with the location of the index mark on the top view in the package drawing, as seen below:



The top view part, by the way, means exactly what you think it does -- you're looking through the top of the package into the pins with a metaphorical X-ray camera.  This means that it matches how you'd map the pins to your PCB footprint.