While Rapid Recovery is transferring the recovery point to the core, the VSS snapshot is stored on the agent. The snapshot is later deleted, which is recorded as a change to the volume. So the VSS snapshot for a large backup being deleted from the protected volume will be tracked as a change on the volume. Because of this, when a large snapshot or base image is taken, the next few incremental will be larger than usual, but steadily decrease in size until they return to normal
