Thank you for your post.
If you maximise the 'view' you will see 8 cyliners on the PC with the smaller monitor.
The intention of this test is to report a quick result, say after a MOT, as a very basic 'health check'. If a cylinder has been identified as suspect, it is advised that subsequent investigation with a conventional compression testing gauge is carried out.
Another check that can reveal more without taking the plugs out is to use the First Look sensor with the Automotive software. Please see here for more details.