It's incredibly tiring when I hit record on the camera then film a segment (either to camera or especially whilst soldering) only to find it was out of focus, I bumped the camera, or my hands blocked your view. A small screen I can place in front of me whilst filming would let me see what was being recorded as I went, saving time and keeping me a little more sane. :)
I love making things and I'm sure you do just as much. I hope my how-to videos can encourage people to build their own machines - and it doesn't matter whether it's an exact replica or your own version of it, just that you have fun, enjoy the end result and might learn a new skill along the way.