Sure, let me describe.  This basically helps get grades into edx-platform without having things be LTI launched.

One (realistic) example would be:  say we have an instructor that has uses a custom virtual machine in their compilers course.  The students write a compiler in the VM, and the VM contains a grade checking script that students can run.  We want to have this script also send a grade to edx-platform.  This scenario doesn't really handle LTI launches (that requires a web app, not a downloadable VM), but it does use the grade callbacks.  So we want to hide any launch interface items.