Speaking strictly from the perspective of a male who is good at spacial representations, it seems you start in the middle of the strap, under the cock and wrap it up and around to the topside..

Note that the two sets of three snaps is oriented with three male snaps vs. two male and one female snap... the female snap engages it's complement (innermost) male snap, on the topside of the cock.

The "northernmost" ends on picture two are not ends at all but "come from" the center of the strap.

The two ends cross and descend down either side of the cock, down toward and then back between the balls, separating them and back up and around each one, rear toward front so the ends can snap into one of the two remaining male snaps of the triplet... presumably.

One presumes the extra male snap is for future use when you can stand tighter... or the leather begins to stretch.