With the advent of digital cameras, the camera lightbox is already obsolete and a thing of the past since the camera lightbox was primarily used for the purposes of inspecting developed film. As you know, with digital cameras you have no need to inspect your developed film because you don't have any.
However, a camera lightbox can become an invaluable photographing aid, even if it's not put to its original intended use. With a few small objects, such as maybe leaves which you might want to photograph, using the camera lightbox to achieve your goal is an admirable idea.
Just get the leaves, or whatever it is that you want, place it on the lit-up camera lightbox, and click away on your camera. The powerful light streaming in through the camera lightbox will highlight all the little nooks and crannies of whatever it is you're shooting. And if you're really creative, you'll be amazed at the amount of stuff that you can photograph with the aid of the camera lightbox.
So if you have a camera lightbox already, don't throw it away. And if you don't have one, then don't turn your nose up at it when you pass it in the store. You might have a digital camera, but it can still help you.