This is an image viewer plugin that does - nothing. It was added to make using Matt Gorners F9 Render script easier to use.
Yes, it really serves no other use unless you make one up ;)
To quote a very satisfied customer:
I've discovered db&w's lens cap plugin creates excellent possibilities for extremely fast high resolution animation rendering - about as close to instantaneous as possible.
I just rendered an 1800 frame animation at 4K in just a couple minutes, with only one machine.
The beauty of it is you can completely remove all your geometry, textures, shaders, GI, lights, disable shadows and use no AA, and the result is virtually indistinguishable from the same scene with millions of polys, textures, shaders, and high settings all around.
It might be a bit premature to call it revolutionary, but it's about the closest I've seen in a good while.
Freed from the burden of trying to create pretty pictures and expansive effects, dbwROTFL has allowed me to become the arteest I've always wanted to be - everything I create now has no boundaries; the burden of explicit representation of… things… now removed - and the viewer can immerse himself in the *interpretation*, while not inconvenienced with the burden of simply accepting the animation (or still) on its own obvious appearance.