The Raspberry Pi isn’t just a very cheap PC, it’s also tiny and uses very little power. So it isn’t too surprising to see one hooked up to a battery and display in a makeshift portable workstation.
SK Pang Electronics sell a wide range of gadgets and components, so when the Raspberry Pi got delivered they didn’t hang about experimenting with it. What they have done is combine a mini wireless keyboard typically used with a smartphone, a USB power pack, and an small LCD monitor usually found in the backseat of a car.