Currently JIGS is mostly used to write server-side non-GUI applications; it's hard to present a screenshot of that!

Here is an experimental GUI example with a screenshot though: check the source code of this tiny GNUstep gui application written in Java: NSWindowTest (taken from the Testing/Java directory in JIGS 0.8.0), and here check a screenshot of it running on my JIGS 0.8.0.

Using the GUI is alpha code; most of gui is not yet wrapped and menus do not work yet, but this example should show you a glimpse of what it will be like when it's finished.