We build stacks into images or other artifacts such as ostree trees. These are the formats in which we release a stack.
For example, we could take a single stack such as a LAMP stack, and build and release it both as SCL rpms in a yum repository, and as container images: indeed, we do so today. It’s the same stack in each artifact. We could add more such formats: virtual appliances, vagrant boxes, anaconda isos or ostree trees, and it would still be the same stack in each; only the artifact / format / image has changed.
The format of the content we deliver may be different in each case, but it’s the same binaries from the same stack inside, and the same stack metadata describing that content.