What does Title & Text control in "Message" tab in Journeys?

Recently, we've been looking at a few different ways to modify and enhance our Checklist/Journey notifications. We've found however, that we're lacking an understanding of what the "Message" tab controls, and what specific notification it impacts.

So far, I've updated the message section of this Journey to look as such:

There is a clear Title and Text, as well as a background image. However, when I look at the "Journey Assigned ORA_CHK_CHECKLIST_INITIATED" alert in alert composer, I can find no tokens referencing Title or Text, nor can I find any $tokens to insert on that notification.