I came up with a second design for a Kindle Fire cardboard stand:

I think this design is interesting in that it holds its shape when the Kindle Fire is not in the stand, but on the other hand, it only works for landscape orientation and not portrait. Also, I notice that the bend for the bottoms of the legs make the cardboard a bit raised when I try to flatten out the cardboard. So there’s some interesting pluses and minuses to both designs.