This does happen on the odd occasion, and it is rather like receiving an unexpected gift, which I suppose it is in some way.
At the time, I was modelling a small gummi-bear type model. Having created the material for the small creature, I pressed the render button without thinking about where the camera was. What a surprise to see this.
It warrants some serious experimentation, but will have to live at the bottom of a fairly long ‘to do’ list.
The material is really simple, but will need an HDRI environment to make this really work.
Just create a simple model, apply the texture and place your camera inside your mesh. Voila! Magic. Now fiddle around with the camera’s lens length and scale your model in different directions without applying the scale.