Jonny,
It's simply a homemade soft lightbox. Best to find a 12X12 cardboard box, cut off one side completely then cut out the large portion of three sides. Glue or tape some white paper to the three holes you have made in the sides you have cut out. This way you can place the box so you can see and photograph through the open front end while positioning your light in on the top, the left or right side. In the examples of my camera photographs, I used an flash off camera with sync cord on the left side of the outside of the box which acts as a soft diffuser and a piece of white posterboard and a piece of shiny, black finish poster board on the inside of the box, curved from top to the flat bottom like a small "infinity backdrop".
You can probably do a search for do it yourself lightbox and get some good ideas but once you get a good size box, cut the top off, you pretty much have an idea of where you are going next.
It may be easier if you cut off a top and side altogether so that you can set the box down over and object instead of reaching in to set the object down and move it but you also loose some structural integrity for thin paperboard boxes. That is your call.

Tonka has been sometimes translated to mean "river" in some Native American languages. And then there are those toys we loved growing up in the '70's. But we got him as a young puppy and decided to keep the name they had given him. Black Bear was originally given another name but we changed it due to witness relocation. You understand.