Cameras in cell phones are a feature, not a substitute for cameras used by people serious about their photography. Photographing jewelry with a cell phone is a ludicrous idea. But articles like this generate a perception that cell phone cameras are capable of things they simply aren't suited for.
The vast majority of people using cell phones wouldn't have a clue about lighting controls and this is not a "portable studio setup". As already noted it's essentially a $5 DIY project involving a cheap mixing bowl, a drill and some rubber bands.
Not that cell phone cameras are useless. A cell phone camera is a purpose built feature that best suits spontaneous low quality photos. Not a bad thing but let's not elevate them to a level a performance they simply can't achieve.
Are you sure this article wasn't supposed to be published on April 1st? One hundred fifty dollars!!! What's that old phrase? Oh yeah... There's a sucker born every minute.