Sorry for the late reply. I suspected my description might have been on the cryptic side. I was referring to the fact that zooming in one direction, followed by

Sorry for the late reply. I suspected my description might have been on the cryptic side. I was referring to the fact that zooming in one direction, followed by the exact same amount in the other, should return you to exactly the same state; these maps don't quite (i.e. they'll sometimes put you in a different location).