If you are referring to my image on SourceForge, it does not auto login. I have found SiriProxy has less permission and errors running as root, which is why everything was installed as root, and the Pi account was intentionally removed. The image is intended as a dedicated SiriProxy.
You can add the Pi account as suggested if you want a user level account to run other applications. Keep in mind that SiriProxy requires a low latency and high bandwidth connection to act as the proxy between your iOS device and Apple servers, so don't expect SiriProxy to be reliable if you are using other high CPU or high bandwidth intensive applications.