To play around with the graph options click the "Customize Me" link.
For more informations also see the docs.
The customization wizard, which opens by clicking the link "Customize me", is not intended to used by end users (and also not on small devices) - it is a convenience helper for developers to better understand the implications of the different graph options.
The link is only shown, when the debug mode is switched on, which is the case here for demonstration purposes. The debug mode writes many informations to the browser console - it should be switched off in a production environment.