Snap down vs. Fold Over - what's the difference?

On one size diapers there are two options to make them smaller or larger.  Most big-box brand diapers feature a snap down rise.  This usually consists of 2-3 columns of 3 snaps.  Snapped all the way down makes them small, snapped to the middle set is medium, and unsnapped is large.  Here are some pictures: 

The top row of snaps will snap down to either of the bottom two rows to shorten the diaper.

Smallest setting (snapped all the way down)

Medium setting (snapped to the middle row)

Large setting (all the way unsnapped)

 Here is the fold down rise:  There are two sets of snaps.  The outside snaps are for the largest setting.  Just snap your diaper and go.  If this makes the diaper too high up on baby, you fold the front panel down and out, exposing the inner row of snaps.  This is called the "fold down rise" - pictures below!

You can see the outside snaps and the back of the inside snaps.

Here is the inside of the same diaper.

This is the diaper with the highest rise (so snapped to the outside snaps)

This is what it looks like with the rise folded down.