Here is a good write up on the Blackmagic Micro Cinema Camera, covering all of its major features and quick introduction to Micro Four Thirds (MFT) lens mount format.

Source: Hands On With The Blackmagic Micro Cinema Camera – HDVideoPro Magazine

Built into the side, the expansion port makes the Micro Cinema very versatile for remote operation, live events, POV and helmet mounts, aerial photography and drone work, or gimbaled setups with motorized or remote controls like the DJI Ronin.

Not only does this port open up connections in a smaller form factor, but offers a way to make it feature complete with existing competitors. One of the many reasons it is on our gear list.

Finally. here is a video review, from 2015.