The demo is using the jbpm.console.directory parameter to detect the directory to load the processes from (and you could change that if you want, or simply start the application server by passing in your own parameter value). Note that this is just a temporary solution, as guvnor integration was still being worked on. With the latest snapshot, you can now use guvnor as the process repository, so deploying your processes (and task forms, process images, etc.) to guvnor will allow the jbpm-console to retrieve them all from there.
Kris