[joyridin']

When you have the E-brake built in the caliper as yours seem to have, it does more than just act as an E-brake. It is also the rear brake adjustment. Over time, when the pads wear, the piston has a ratchet mechanism so the piston doesn't have to travel as far when the pad wears. Without this, your pedal will get really low after some point in time.

That picture is hard to see, but it doesn't look like they have the mounting for the cable.