When you're done specifying options in the GUI, or when Revisor thinks it can go ahead using the options specified in CLI mode, it takes the list of packages selected from either the GUI or the kickstart %packages manifest.
Not getting too deep into details here, yet, because some of these things are routines shared with other composing modes, but here's a few additional considerations Revisor makes when doing the package selection.
Normally, a kickstart %packages manifest only allows you to select package names. With Revisor though, you can select exact package NEVRA to select a certain version or architecture for the package that you want. Additionally, if a package is not available, Revisor searches the Provides of the available packages.
