The Kodak Step Slim printer is a very specific device, for a very specific audience. It's not dissimilar in size to a mobile phone, albeit with a squarer shape. It runs off a rechargeable battery, so you can use it pretty much anywhere. It uses Zink (as in 'zero ink') paper, which is embedded with special color crystals, so you don't need to load it with a separate ink cartridge. And it allows you to generate small (2 x 3 inch) prints of the photos on your smartphone or social media accounts, via a free app.
In other words, this is a pocket-sized portable printer you could bring to a wedding, party, festival or any other event, and use to print out pictures you've just taken, as a nice gift for others. A bit like the Polaroid cameras of old then, only it doesn't contain the camera bit, only the printer bit, and the prints are much smaller.