Goodbye, cleavage. Hello, décolleté. There is one style of low neckline that looks modern, right now, and another shape of low neckline that doesn’t. Oddly, the more modern shape is the square neckline, which was all the rage in the late 18th and early 19th centuries, while the plunging V-neck, which is 20th century, looks old-fashioned by comparison. Strange, but true. You could blame Netflix’s Bridgerton, with its feast of pastel-coloured, squared-off necklines. You could point to the demise of lift-and-squeeze Wonderbra-esque engineering that backlit old-school cleavage. Or you could observe that a square neckline is the perfect foil for that staple of modern fashion, the puffed sleeve, and has come into fashion for that reason. Maybe you don’t care at all, which is entirely your prerogative. It’s your neckline, your skin, your body. The square neckline is a mindless diversion, nothing more than that. A summer frippery, like a new flavour of Magnum or a new song on the radio. It is entirely non-essential, harmless fun. Personally, I’m very much here for it on that basis. A year that has been decidedly lacking in novelty value has reminded me of how cheering a little novelty can be. I would go so far as to say that the resolute silliness of the square neckline makes it particularly enjoyable to wear. This look has none of the determined sexiness of the plunging V-neck, which now comes with vaguely predatory-power-dresser overtones. It is just quite pretty and quite jolly, neither too warm nor too cold. I prefer clothes that cover my shoulders, to avoid tedious bra strap micromanagement, but I find that bright or patterned summer clothes can easily swamp me if the neckline is too high and the sleeves are too long, and there’s just my head and hands poking out of great reams of floral fabric. Better to show a little skin, which reminds the world that you are a human, not just an outfit. You can go full cottagecore and wear your square neckline with a loose tiered skirt and a basketweave handbag. Or you can steer it towards a Bluetooth speaker, Deliveroo-to-the-park urban-picnic vibe by wearing it with jeans and trainers. I’m going with proper trousers, subbing it in for the more traditional cotton button-down shirt. It’s hip to be square. And, more importantly, it’s quite fun. Jess wears square-neck top, £42, warehouse.co.uk. Heels, £165, reiss.com. Trousers, her own. Styling: Melanie Wilkinson, assisted by Peter Bevan. Hair and makeup: Sophie Higginson using Ouai haircare and Vichy.