Intro messages for mods. A beep, a message box saying "Courier stash something something."
There are mods to silence the courier stash and the dlcs, thankfully, because that's over four pauses and beeps right there. But once you've got a big mod list, there's another fifteen of these beeps and message boxes... they're still going on through most of the chargen in Mitchel's house... beep, pause in mid sentence, message box, ok... repeat a few seconds later.
What are they there for? I've never made any major mods, not even close, but I'd never include something like that personally. But even Obsidian and Bethesda did it with their addons. Thank goodness the vanilla ones could be silenced.
But, I guess, maybe some people like the pauses and message boxes for a few minutes? That has to be it, right?

I think they were meant to be symbol showing that the scripts were running for the DLCs.

Wow, there are a LOT more mods already for this than I'd realized. I must have typed in the wrong word when I searched for it last time