The BMPN explorer overview is a very nice way to structure the flow of a process. With the conformance module you then can get data which activities are not wanted etc.
What is a real pity that this is not visualised with the BPMN explorer itself.
Of course you normally would then take only one variant to show the difference against the modelled process.
You normally have two situations: you have added on activities or you have missing activities.
Underneath two pictures of theses situations:
Maybe others have more wishes about this topic…