Hoistop - As I've said before, I've never seen the inside workings of one of these servo actuators.
The diagram is a schematic of what I think the TR actuator looks like judging by the shape of the one fitted to an AW169. I've also provided an AW169 'technical' description that I have found. I am assuming that 'connected by a flange' is describing how the cylinders are connected together.
"A Linear Tandem Hydraulic Actuator, consisting of a single jack with two pistons housed in two different cylinders mutually connected by means of a flange; the two cylinders receive the control flows from the two control valves and provide the force necessary to drive the pitch control mechanism of the tail rotor blades."