Much of the focus with containerized data centers has been on mega-facilities that can house dozens of shipping containers.
Another use case where containerized data centers could make sense is in retrofitting buildings, though it may be somewhat counter-intuitive.
Building a state-of-the art facility can take a long time, but clearing out an open space and then lifting in a container could be a much faster approach to getting an optimized facility installed in a building than trying to get it built in place. Furthermore, it's possible to replace a set of equipment the same way.
This could be used with a single container, or there could be multiple containers placed together on the same floor of an office building.