I thought the same thing and I'm still not convinced that's not what's going on. I remember in the '90s so many people were putting chains to their wallets, you know wear your money is... Well your cell phone is probably attached to one of your accounts, so it's money. This weirdly makes sense to me.
I think it makes perfect sense, and a cool retro throwback. Fashion is cyclical after all! But I think the other poster was correct and she just has it fed through 2 belt loops.
I just heard today that you’re considered old if you wear ankle socks now. It was the opposite when I was younger, not wearing ankle socks made you look old and out of fashion.