People caught in 4k - Caught in 4k: what is it? What does it mean?

This the most HD shit ever! For example, on September 11th, 2020, Twitter user Tmulla0 made a post using the expression that gained over 90 retweets and 2,000 likes shown below, left.

Karen500 I just pissed on a guys shoes and spat in his drink after my came back positive Karen500 We need to limit the spread of COVID-19 Michael69420 RT "I just pissed on a guys shoes and spat in his drink after my COVID test came back positive" This you? If a woman sends you a clothing item, say you love it.