I'm trying to think of what other products/projects I'm aware of using optical coupling for configuration - the Bloomberg B-Unit used/uses a similar screen-flash strategy for authentication, and some first-person drone cameras can leverage adding/removing the lenscap to navigate the menus, but this configuration mechanism isn't as popular as I'd expect it to be given how clever and straightforward it is. This is a really cool project!
The later Psion (or Cannon?) PDAs used monitor-flashing as a way to send serial data to the PDA from PC -- this was used for quickly filling in address books and so-on.
When I used it then I thought 'Wow, this is neat -- but probably dangerous for epileptics.' . Much tidier than dealing with an RS232 interface or the like -- just use a photodiode.
edit: it was the Sharp Zaurus series that used the optical data transfer -- I think. it's been years and I used to be too into PDAs
edit 2 : Royal also had a PDA series with optical transfer; but i'm not sure whether or not Royal made their own hardware products.
edit 3 : I found the Royal organizer : 'Point your FL95 PC Organizer at your desktop PC monitor. Watch as flashing bars of light send information to the FL95 PC Organizer.'
Not configuration, but some banks in Europe have or had devices to authorize online banking transactions using the principle: A standalone device you put your banking card in and hold it up to the screen, the banking site blinks the transaction information, you confirm the transaction on the device and it gives you TAN code to type in.
