Lubricate Loaded Calipers? Brakes dragging intermittently

Redfish--but the way this caliper is designed it seems as if the only moving part is the piston which pushes the inner pad against the rotor. I'm a newb, and certainly no brake expert, but I don't see how the outer pad can do anything except just sit against the rotor if the only moving part is the inner pad and piston. I'm probably just missing something..

A floating caliper slides forward and back to center itself to the rotor either via machined ways or on guide pins though it. A fixed caliper will have pistons inner and outer, such as the KH 4 piston calipers.