Click on the "launch binder" icon to start the notebooks. Setting-up the working environement on the binder service can take a couple of minutes. Binder will automatically shut down user sessions that have more than 10 minutes of inactivity.
To download a file (like a figure), select File -> Open...
in the menu. This opens a new window with a file manager. Tick the check-box of the file and select Download
.
More information about Binder is available in the Binder FAQ.