It says that your Shame Threshold is one higher than normal. Add a bane to all Charm checks.

How does this actually work? What is Shame Threshold?

This comes from the Lure of Power supplement which focuses on social activities and Slaanesh.

You can see a summary of the rules of Shame and my houserules here:

https://the-awkward-companions.obsidianportal.com/wikis/social-combat-duel-of-wits

Thanks, that's a big help!