External enclosure connected via usb-c. It’s cheap and effective.

I’ve configured something like this in FVWM2 a long time ago. It was neat for a few hours, but I don’t really see the benefit over regular virtual workspaces.

in i3 I already switch workspaces with mouse wheel on the status bar, which is super easy and seems easier panning around with a mouse.

You would need a locked down device and be physically present at the viewing. Otherwise they can just take a photo of the photo with their phone and share that.