Currently, PiP-textures can only display live-feeds from cameras.

It would be good to have a command that can create a snapshot from a camera and save it as temporary texture.

To apply the same logic as with rendertarget, the snapshot could be created like this:
mycamera cameraEffect ["INTERNAL","BACK","snapshot(512,512,mysnapshot)"]

And used as texture like this:
#(argb,512,512,1)snap(mysnapshot,1.0)

This could be used for several things but especially for dynamically generated intel. It could also be included in the document-feature from Zeus.

For example, it could also be used in a script that allows players to go on a reconnaissance mission, take photos and show them to their teammates back at base to plan an attack.