There is no screensaver provided (or planned) for Test4Theory.
But you can see many of the computed results via a friendly web application which is provided in the virtual machine. In order to see the results you will have to press the "Show graphics" button in the BOINC Manager (if you are using the new VBox Wrapper) or (for the old CernVM Wrapper) open the following web page: http://localhost:7859/
For more details, see "How can I see the progress of the experiments?".
Here you have an screenshot of it up and running: