I can see my character in my head. How her hair looks. What shoes she is wearing. But you can’t. So it’s up to me to create a very clear, vivid image in your head. Fashion is important because a balding older male with an advanced medical degree probably wouldn’t be wearing black leather pants that lace up on the side. He probably wouldn’t be wearing tie dye socks and screen print shirt with a picture of an semi automatic rifle.
If I am writing about a damaged girl with a dysfunctional home life who struggles to stay off drugs, I wouldn’t paint the mental image of her wearing a pink sun dress with little white polka dots. Nor would she be wearing a tailored business suit and Jimmie Choo shoes.
So you give hints about what they are wearing. And they aren’t going to be wearing boxer shorts enjoying a Cosmopolitan on the balcony of a Nordic chalet during a blizzard. No matter how romantic it might sound.