That's signaling, like wearing expensive clothes. Countersignaling means dressing like a bum in high-class circles and getting accepted anyway.
Edit: and otoh I would consider "Boss is in shorts, t-shirt and sandals" as just plain signalling, because I grew up in a world (my favourite anecdote was working with a Hawai'ian VC who would classify meetings as "socks" or "no socks") where in any given business situation, those who have the gold dress down and those who pitch for it dress up.
With countersignaling there's an extra level to the game where your message has the form "I have this quality over and above merely affording the first-level cost" -- now the cost you're paying is the risk of being taken for riff-raff. Those with more of that quality, whatever it is, have to be better at pulling that gambit off, for it to work as a countersignal.
conjugation: "They are riffraff. You are sloppy. I am sprezzatura incarnate."
essentially, more status game plays