That screenshot appears to be from World of Xeen. While the games use similar engines, they are not identical, and I believe the "change view" feature isn't in MM3. In World of Xeen, this would allow you to switch between the Wizard Eye view and a similar view that only shows squares that have been mapped by the Cartography skill (but works even without Wizard Eye active). It's a nice feature, but unfortunately not one they thought to implement for MM3.

Also, MM3 allows up to 8 party members (2 of whom are hirelings), while the Xeen games got rid of hirelings, so party size is capped at 6. This freed up some space on the user interface, so the developers decided to put direction icons there.

In summary, the reference card is for World of Xeen, and while the games are similar from an interface (and game engine) perspective, they are not identical, and those differences are what's tripping you up.