Not been on the QV2 yet but with other cruises my experience is they either put the show on after the end of 2nd sitting usually around 10.30 or they start the show around 7 p.m. and then onto your meal afterwards, it is now fairly common practise to have 1st/2nd sittings on the majority of cruise ships but others will perhaps come in with more info.
1st sitting for dinner starts at 1800hrs lasts about 1 3/4 hrs not rushed in fact it can be rather slow sometimes, 1st show starts 20.30hrs best to be seated by 20.15hrs, 2nd show starts 22.30 hrs .
The shows are organised not to clash with dinner, so all can see them as they are performed twice nightly, There is ample time for dinner and nothing is rushed, I have had early and late sitting and prefer the late as you have more time to change and chill before dinner, but that is my personal preference, if you want a pre dinner drink or stroll round the decks then there is time. dont worry you will enjoy and not miss anything.
Thank you for taking the time to comment. I won't worry now, but have a fab time. Sharing a table again with people I dined with on my first cruise last year.