Watching Celine ’s recent fashion shows, you can feel how much artistic director Michael Rider enjoys playing with clothes, toying with proportions, scale, color and what he simply calls “flair”: the unexpected effect of a fringed headband; a shoelace-thin belt for a coat, or — what the hell? — a length of glossy fabric wound around the neck and head, or clutched in one hand.

What’s up with those rectangles of satin?

“We talked a lot about handkerchiefs and pocket squares and those clichéd codes of menswear but that don’t feel fresh,” Rider replied. “At end of the day, I’m not going out with a pocket square, but I like flair.…