I've only done Year 9 and Year 10 systems engineering, but we did some stuff with putting together circuits and other electronics stuff. Did a bit of metal work kind of stuff as well. We also looked at motors, how the internal combustion engine functions etc. Obviously it would be a bit different in how it's taught in VCE.
I know in 3/4, you have a major production that you plan, design and construct throughout the year. One guy at my school built a hovercraft. A couple of years ago somebody made a go-kart, using an old lawn mower engine. The final projects they come up with are pretty impressive. I would have kept doing it, but I prefer my maths and sciences.
Everyone else in my physics class does systems. So yeah I definitely know they do a lot of work with building circuits and motors (they all understood Motors, Generators and Electronics pretty well in Physics). Other than that, I don't really know beyond what our course handbook says.
Our course handbook mentions 'underlying fundamental physics and applied maths concepts' (would be pretty straight forward stuff), 'a mechanical subsystem integrated with an electrotechnology subsystem' and 'design factors' and then mentions Mechanical and Electrotech systems again.
Also: Found this website, has some pictures of past student projects (some people build robots as well) and other resources for the subject:
http://eduswaplearning.com/