Earlier quoted context omitted.
When projecting song lyrics at church, and the worship leader says: "let's sing the chorus again with 'we' instead of 'me'" and I suddenly have to freeze frame, edit the text, and bring it up as quickly as possible. I'm sure there are other use cases for a freeze button, and the idea of having it as a separate device is something so obvious to me that I'm surprised it doesn't already exist.
Aha, but the general idea is still "show the current thing while I'm futzing around to make the next thing happen"?
Yep that's the gist. I've also seen some small events using the computer background as the static logo; they can prepare the next deck while freezing the logo up on he screen.