I have followed the instructions onhttp://www.eclipse.org/gmt/epsilon/doc/articles/eugenia-nodes-with-images/ and I have gone as far as running the editor again with this custom figure code. For that, I had to do some additional work on the manifest file of the Eugenia project (http://screencast.com/t/u6jbe3W9Cln3) and also I have introduced a dependency from the *.diagram project to the Eugenia project. Finally, I have included the images directory in the *.diagram project and I have included that images folder in the build configurations (bin and src) in the plugin.xml of that project (http://screencast.com/t/RC5mtpoPCG9). These steps are based on some non-Epsilon-specific google searches and my personal intuition so please let me know if I have done something too much or too little (I am not an Eclipse plugin expert).
I am currently facing the problem of a NPE when using the Eugenia based editor. More specifically, the essential line with the imageDescriptorFromPlugin call returns null. Therefore, it seems that still I am missing something in my build configuration. I would be very grateful when learning how to fix this. Perhaps http://www.eclipse.org/gmt/epsilon/doc/articles/eugenia-nodes-with-images/ can be extended with some build/deploy instructions or pointers for Eclipse plugin dummies?