The logic of this tweet seems to go along the lines of: "it's OK to have some non white people on #NMUKITVGMB - in a tokenistic kind of way (because after all, it's not like they're essential of anything) - as a type of 'decoration' / evidence used to stave off criticism of being racist, but of course, because they're not fulfilling an essential role - the more of 'them' i.e. #MetaphorVersusUsThem that you have the fewer 'legitimate' i.e. white people that you have to do the actual job". The 'give away' is the characterisation of a "British white person" i.e. a 'legitimate British person' (pointing to the idea that #IdentityWhite is an essential attribute of Britishness). The tweet is an overt example of deep-seated #OtheringDiscriminationRacism and strongly implies that the author feels under attack i.e. #TheoryPoliticsOfFearAnxietyOfVictimisation as they struggle (resist) to engaged with contemporary society i.e. a #TheoryPoliticsOfEternity if ever there was one.
Interestingly, the image used to illustrate the tweet is taken from a video, which shows #OrgClassifPPUKConservativesBorisJohnson, moments before being infamously stuck on a zip-wire while intending to celebrate/raise awareness for the UK winning its first Olympic gold medal in the #2012_LondonOlympicGames i.e. an image that has become synonymous with #TauntSnatchingDefeatFromTheJawsOfVictory i.e. https://www.theguardian.com/politics/2012/aug/01/boris-johnson-zip-wire Presumably, the image is meant to signify a sense of #PoliticsNationalismConservative re #TauntFlagWaving etc.
Tweet responding to tweet by #WebsiteConservativeHomeBellaWallersteiner about a supposed 'Unite for Freedom rally' i.e. https://www.conservativehome.com/platform/2021/05/i-attended-the-freedom-march-yesterday-im-no-anti-vaxxer-or-covid-denier-i-just-want-a-return-of-common-sense.html Who is identified as: "Bella Wallersteiner works as Senior Parliamentary Assistant for a Conservative MP" where the anonymous MP as per the earlier article is identified as #OrgClassifPPUKConservativesGregSmith: "Bella Wallersteiner is Senior Parliamentary Assistant to Greg Smith MP." https://24plusnews.co.uk/category/greg-smith/ (3 August 2020). Note that this link appears to be the original version whereas the one available on Conservative Home appears to have been updated since (or, at least this seems like the most plausible explanation for the discrepancy). If so, one wonders why the reference has been anonymised.