LibreLAB is a prototype of a workspace - "place of convergence of subjective technology". What technology does to you and what technology do for you has a completely different perspective when technology is libre in nature, this demands for more responsiblity in nature than other forms and much more accessibility to everyone who have inclination toward such. Prototype of a workspace inherently means constant strive for betterment.

Smartphone(ARM)

Smartphones which are part of everyones life comes embedded with GNU/Linux and different rootfs which combines together to form different distros for smartphones. Some of the previews of such distros on smartphone are qtmoko, DoF, AoF, Firefox OS, ubuntu touch.
Developing application on userland is challenging but if one wants to get involved in developing custom ROM images for such devices then the area of concern widens further more which includes generating kernel image for the device(support for the device component in the kernel), generating bootloader which also has to satisfy the devices spec it becomes even more challenging when different flavours of bootloaders are available like uboot, qi with boot menu. Now comes the rootfs ROM image which comes in different flavours like qtmoko, DoF, Android etc. All these when combined together provides a clear cut basis on what runs on the smartphone(Application processor)[This very much is the case with all the smartphones] and who runs the ROM images or whether such custom builds are allowed?[not all phones allow this]  
Then there is the mobile station(MS) open source GSM stack which can be flashed on the Baseband Chipset(BP) chipset which provides the opportunity to learn about the real time GSM stack on a mobile phone giving insight into how GSM network works(a developers point of view)

Desktop (X86)

For any kind of development(those mentioned above as well as embedded) involves the conspicuous entity namely desktop without which every thing mentioned above fades away. There is also very much involvement of how much open the technology is, which will allow any self directed ones to get involved in learning process, provide the necessary insight into the tech as one finds fit without the blockage(superficality which looms predominantly) which distances the user from the actual info.
actual - low level abstraction
superficiality - high level abstaction
It is a steep learning curve to go from the high level abstraction to low level but enthusiast just find a way to comprehend things in their own way.
Apart from all these, the routine use of desktop to act as a development tool in the hands of a developer/programmer for/on desktop application is still pursued.