Raspberry Pi is a microcontroller board witch doesn’t have any user interface. All things has to be plugged in have control. As Linux machine it can be controlled via secure shell (ssh) interface which require it to be connected to internet or via serial interface. But if you want raspberry to be more stand alone device you need to think about some user interface. Jason wanted his RasPi to be manageable in some way without auxiliary devices. So he started project headless.
Ss you can see this is a shield for Raspberry Pi which connects to GPIO header and with enclosure it makes pretty good standalone device. Shield carries four line text LCD, several pushbuttons and experimental COM interface built using couple transistors. As operating system for Raspberry Pi Jason selected Arch Linux which seems to boot faster and is lightweight. His custom application runs after boot and gives access to many system parameters and configurations. With battery attached at the bottom it makes pretty good handheld device.