Which problem does it solve?
It solves the problem of having discussions around particular outliers on Visualizations. You can basically select any mark on a dashboard, create a new comment for it and review what other people discussed about it.   
                                                
                                                
                                                

How does this look like? 

How can I leverage it? 

1. Extract both Extensions into “My Tableau Repository/Extension”
   Download Extensions here
2. Extract Xampp (Webserver + MySQL directly into your C: drive)
   Download Xampp here
3. Start C:/xampp/xampp_start.exe as administrator
4. Start Tableau Desktop 2018.3.1 and Open Up one of the following workbook
   Download Workbook here

Troubleshooting

• Port 8888 is already in use before starting Xampp
  (Change the port)
• You’re using an older Tableau Version
  (Migrate the workbook to an older version, but keep in mind that the version needs to support Tableau Extensions)