If you have two layers installing an individual packages like /nix/store/x and /nix/store/y, stacking them as [x, y] and [y, x] would result in the same docker image contents, but docker will generate different hashes.
> If you have two layers installing an individual packages like /nix/store/x and /nix/store/y, stacking them as [x, y] and [y, x] would result in the same docker image contents
This is an assumption which is valid for nix, but not for most of the package managers. Whenever such assumption can be considered correct, Dockerfiles can achieve similar results using multiple stages, but you would probably need a pre-processor to have a stage for each package. Something like an `INCLUDE` directive could help too: https://github.com/moby/moby/issues/3378.