Guardian news,not guardians of news

Take a look at @neilroytaylor’s Tweet: https://twitter.com/neilroytaylor/status/851533348497489921?s=09

Well this Unicorn is finding this most perplexing. What are they guardians of? Truth, fairness, unbiased reports? 
Can any human please explain? I get lost with your foreign language sometimes, & my pet human is asleep.