This access panel has taken different forms over the last few iterations of the mini, with the 2010 model offering a simple twist-to-open design and the 2014 model requiring a special prying tool (literally, a modified putty knife) to open. Around the edges of the panel are cleverly concealed vents for air flow, and the simple black surface has 'Mac mini' imprinted on it. On the bottom of the Mac mini's aluminum chassis is a black plastic disk, which does double duty as both the foot for the compact PC as well as a cover that opens to provide internal access.
The power supply has been enlarged to provide the necessary power to the new components. The design has larger vents and a bigger fan, doubling the airflow to better cool the processor. To accommodate the updated hardware inside, Apple had to change some of the internal design, as well.
The littlest Mac has gotten a pretty stunning makeover, starting with the space-gray anodized finish.