I love clothes with pockets, even though I don’t actually put anything in them – apart from a phone occasionally slid into a jeans back pocket. I carry more stuff than would fit in pockets, so I am a bag person. But storage is not the point of pockets, in fashion. What I like about pockets is the mood music they bring to an outfit.

When a dress has pockets, it takes on a different vibe. It doesn’t matter that you can’t carry anything more than a lip balm in the aforementioned pocket without ruining the line of the dress. Just the fact that they are there, for you to jam your hands into when you feel awkward at a party, or to put your office swipe pass in so you can carry a cup of coffee, changes the personality of the dress. This dress is your friend.

Pockets have been the fashionista’s favourite hidden detail for a while. The trousers I am wearing here are an old straight-leg pair from Cos that I love partly for the pockets on the side, which you can’t see here, but which flatten and structure the waist in a pleasing way. And at Chanel’s spring summer show, Kaia Gerber wore a white shirt with large white patch pockets, emblazoned CHA and NEL in bold black capitals, jumpstarting a trend for patch pockets all over the high street – see this rather excellent olive overshirt from Bershka, a shirt-jacket hybrid that is the perfect weight for the in-between season. There are patch pockets on brightly coloured short-sleeve shirts, and on this season’s ubiquitous boilersuit.

Patch pockets are often breezily described as “utilitarian”. This isn’t strictly true, because you can’t actually put anything in chest-height patch pockets without making yourself a weird shape. Utilitarianism in fashion sits somewhere between actual utility and the philosophical, John Stuart Mill sense of the word. It is not so much “useful” as “with an air of usefulness”.

But even an air of usefulness has its uses. Mood music matters, in what you wear. Whether it’s a patch pocket or a platform heel, an epaulette or embroidery, details make a point even when they are just for show. Patch pockets have a good vibe – and you never know, they may even come in useful. After all, holding your lift pass between your teeth isn’t a great look.

• Jess wears leather shirt, £49.99, bershka.com. Sandals, €250 (£216), aeyde.com. Trousers, Jess’s own. Styling: Melanie Wilkinson. Hair and makeup: Samantha Cooper at Carol Hayes Management using MAC Cosmetics and OUAI.