We're used to seeing some fancy mechanics driving the kickstand hinge in these Surface Pros, but this time we're treated to even more fancy mechanics.
The SSD cover sits on one side of a tiny see-saw, waiting for a friendly SIM eject tool or paperclip to come along and sit on the other side. When that happens, the see-saw pushes the SSD cover away from the case, and bam! Just like that you can upgrade your storage.
When we're done at the world's smallest playground, we move over to the SSD interface and SIM reader, which come out as one module.