I think what they mean is that the blinds and flyscreens fitted to the Clubman are the concertina type. We had them on our previous caravan (Abbey GTS), and you can't use them both at the same time as you can with the "lower" spec Lunars. Therefore, at night, and if ventilation is needed when the blinds are being used, the flyscreens are rolled up (or down whichever way they're fitted) and creepy crawlies can get in. To prevent the mozzies, we used the flyscreens and wait for it ........... drew the curtains! How twee.
Personally, whilst the concertina type look posh, in practice I prefer the "cheaper" version.