Scallywagger, I think there are lines running to the wheel or tiller In the cockpit. They may be fewer or smaller but the report suggests the lines transfers the power from the unit to the boats steering.
I read the following about their 700 model.
“The energy required to move the wheel or tiller is thus extracted from the waterflow by the servo blade.
Several different line circuits can be used with the SAILOMAT 700. In contrast to previous systems, the two pull-pull lines from the pendulum body are initially running upwards from two unique 'wing' lever arms attached to the pendulum. This permits simpler block positioning, and keeps the transom or walk-thru region more accessible and clean from 'line-clutter' often seen with other systems.“
The lines have to run somewhere.