Precomputed/Canned Lip Sync: "With Offline Model" option

When generating a precomputed viseme asset, in Unity, from an audio clip, there are two menu items under "Oculus/Lip Sync":

1. "Generate Lip Sync Assets"
2. "Generate Lip Sync Assets With Offline Model"

The documentation only mentions the first of these. 

https://developer.oculus.com/documentation/unity/audio-ovrlipsync-precomputed-unity/

So, what does the "With Offline Model" part mean? When might (or should) one use it?