The Usage Panel is a Looker-created dashboard that presents usage information about your Looker instance. Admins can use the data to better understand how their users utilize the application.
The Usage Dashboard is accessed from the Admin page of Looker:
You can create a PDF of this dashboard by clicking the gear and choosing Download as PDF.
From this dashboard, you can drill into metrics and elements like any other dashboard:
All of the information in the Usage panel is based on a LookML model called i__looker. Understanding that model can help you build useful, custom reports around the usage of your Looker instance and information about saved Looks and Dashboards. See our Creating Looker Usage and Metadata Reports page to learn more.