If you have added some Layer Stack Preview symbols and then changed the design so that the symbol is out of date, you can update them using this option (all instances will be updated). You do not normally need to do this when plotting because it is done automatically.
Shortcuts
Default Keys: None
Default Menu: Context menu
Command: Update Layer Stack Previews
Locating this option
Available from: Context menu > Update Layer Stack Previews option
Using this option
Select the Layer stack Preview in your design and right click to find this option on the shortcut menu.