This is PolarisOS. It's a cancelled edition of Windows Core OS that was designed for Desktops and Laptops. This image is early enough to not include much more than the OS itself. It comes with no shell, and won't load any. 
You need an ARM device to boot this, and you need to sideload drivers before first boot. The wim is bootable, but you can also install it directly by applying index 1. 

To install on a phone instead of an arm tablet, go to catalog.update.microsoft.com, find the latest firmware for your phone, download all MainOS cabinets for it, place all of them in a folder, and run dism /Image: /Add-Package /PackagePath:

To install on an arm tablet, get the tablet drivers, and run dism /Image: /Add-Driver /Driver: /Recurse

Upon boot, pressing the power button will shutdown the device, connecting the device over USB will expose a diagnostic interface, which you can use to open a command prompt shell afterwards