The pictures below show a picture of the rotor (yellow) / stator (green) interface for a case with rotational periodicity. A small source has been placed on the shroud surface of the rotor causing both surface clustering and also a thinner boundary layer mesh.
Without the sliding interface feature, this clustering is localized to the region of the source.
Turning the sliding interface feature on, the clustering is spread over the entire circumference of both the rotor and the stator on the interface. Similarly, the reduced thickness of the prisms has also spread over the entire interface.