I've added a little more detail here:
So I’m looking for a video, animation or presentation that convincingly demonstrates how easy it is to create, edit and manage pages, articles, menus, text, images, embedded content, etc. etc. with WordPress. The back-end, indeed.
The best way might be for me to go and live-demonstrate the back-end on a WP install, but I think they prefer a file or link that they can share (time-shift) rather than calling everybody into a room or conference call.
Any suggestions greatly appreciated!