Unfortunately, the person above did not have the benefit of two umbilical cords and thus two belly buttons. Rather, they're wearing a belly button sticker affixed above the one true navel. Why? Because when wearing a shirt that exposes the midriff, the higher belly button is meant to give the illusion of a shorter torso and longer legs. The faux-navels temporary tattoos are apparently a growing trend in China, selling for less than $1 for a sheet of them.
From Oddity Central:
Some Chinese news outlets credited the unexpected popularity of belly button stickers to Chinese traditional medicine, which states that the lower abdomen must be kept warm to preserve the overall health of the body. By keeping the fake navel exposed, users can wear high-waisted pants that cover much of the stomach, while still rocking garments like crop-tops[…]
"These stickers are not easy to drop off; they're non-reflective and even waterproof," one person wrote on Weibo. "I'm willing to call them the most successful invention of 2023!"
"This isn't just a fake belly button sticker; it's a 'cheating tool' for bidding farewell to my 50-50 body proportion," someone else wrote on Douyin, the Chinese version of TikTok.