First container is equivalent to a space, an environment, software and some files can be run in the environment; and the mirror: ubantu a system is not running a mirror, while the vessel is running mirrored environment, that mirror must run in a container.
the door docker container technology, may consist of a plurality docker containers.
Mirroring each container with a corresponding, but also can be said that multiple mirrors mounted in a container, like a lot of our software running in a virtual machine environment