FLORENCE, Italy — While the wider world may have doubled down on cargo shorts, flip-flops and whatever passes for a male uniform in the world of open-space workplaces, here on the streets of this Renaissance city and throughout the trade pavilions crammed inside the 25-acre walled Fortezza da Basso for the huge Pitti Uomo men’s wear fair, it’s dandy time.

Suddenly, it seems, every cobbled lane (and Instagram feed) is chockablock with men in Homburg hats or straw boaters, suits with nipped jackets and pleated trousers cropped short to reveal two-tone spectator shoes. There are capes and canes and foulards and billowing pocket squares, beards of every imaginable cut and even waxed mustaches. Sometimes, seen walking two or three abreast, the Finnish and Korean and Russian and Chinese and Japanese buyers or vendors seem dressed as if for some arcane form of cosplay. All of it is decorative, anachronistic, highly refined and considered — and more than a bit silly.

And it has all begun to change.

Far too little is said about fashion’s relation to Newton’s third law of motion, the one that posits for every action there is an equal and opposite reaction. Indications are already visible as Pitti Uomo begins — 20,000 visitors and 1,240 brand representatives descending en masse on the tiny Florence airport — that reactive change is coming to men’s wear. The dandy is dead. We are entering the age of fugly.