> This question could be dismissed by saying that Nix and Docker are different tools that solve different problems.

> One is a container deployment toolkit and the other is a package and configuration manager.

My reading, based on the mapping from the arrangement of the 2 words Nix and Docker, is that Nix is a "container deployment toolkit" and docker "package and configuration manager".

Of course, this interpretation is wrong.

Further, even if applying container deployment toolkit as a description to docker, it still misses a core part of docker, I.e., docker is also a container image building tool kit. The building part and the deployment are for different steps with seemingly equal importance.