This function helps preview the dashboard widget's function. 

You can navigate to the Administration - Dashboard Widgets menu option. 

The Dashboard Widgets UI is rendered as below. The widgets are grouped and listed as a table showing display name, description, and validation status columns. You can use the Search box to filter the list.  

Select the dashboard widget from the list, and click the View - Preview menu option. 

The Widget UI Preview popup window is displayed, rendering the widget's function for viewing.