If you just want to skip straight to the cutting action, fast-forward to the 0:41-mark of the video.
It's genuinely terrifying seeing water slice through something like it isn't even there. Admittedly, the camera isn't made of particularly tough materials, but at no point does the jet struggle or have to stop.
As for what's inside... well, there isn't much. Modern cameras are mostly glass and mirrors, with the actual electronics taking up very little space. Of course, nothing really survived intact.
There's an entire channel dedicated to this stuff, so if you want to see more items dissected, there's no shortage of videos.