Kevin,
The Dragonfly normally has 2 wires going to the live side of the battery, and a short, single wire to the earth side of the battery. This single wire is usually just long enough to connect the earth terminal to one of the battery carrier mounting bolts.
From the photo you posted, I would think the terminal with 2 wires goes to the live side of the battery (one wire is the live feed up to the ammeter - the other is the direct feed to the horn, as a poorly adjusted horn could create an overload if it was wired through the ammeter). The terminal with the single wire is the earth, and probably goes up the harness to be earthed in the headlamp nascelle (to provide a more reliable earth connection than that through all the joints between engine, frame, petrol tank and headlamp nascelle).
Regards,
Eddie.