The cloud-native part is that it's built with tools and things you'd see in cloud-native like OCI containers, gitops, etc. Here's the containerfile as an example of how it's put together: https://github.com/ublue-os/bluefin/blob/main/Containerfile
And then all the developer patterns are cloud native like devcontainers instead of using the host packages, included k8s, podman, and docker tooling, etc.