/Add-Package /PackagePath: Installs a specified .cab package in the image. Multiple packages can be added on one command ...

/Add-Package /PackagePath:

  Installs a specified .cab package in the image. Multiple packages can be
  added on one command line.
  /PackagePath can point to either a .cab file or a folder.

    Examples:
      DISM.exe /Image:C:\test\offline /Add-Package 
        /PackagePath:C:\test\packages

      DISM.exe /Image:C:\test\offline /Add-Package
        /PackagePath:C:\test\packages\package.cab