The webui does not deal with empty states at all.
A document has been drafted with guidelines for how to deal with this.
In a nutshell, we've created a component specifically for dealing with empty states called entity-empty. It will be rendered inside where ever it is appropriate. Mostly pages but also in individual elements like empty tables etc.
Here is are some examples of areas that could benefit from entity-empty:
- Entity-table - support generic and custom messages
- Credentials/Backup Credentials - each card
- Dashboard (if configured to hide all widgets)