Leaf carving involves cutting away at a leaf until it reveals an image. This is a craft practiced by Nature's Art, a studio in Hengshui, China. At the link, you can view several other examples as well as instructions on how to make your own.
http://www.longal-craft.com/leaf-carving-art.html via Make | Photo: Nature's Art
In which case, it is really cool.
1) Find scrap metal.
2) Clean scrap metal.
3) Dry scrap metal.
4) Sort scrap metal.
5) Build car.
6) Profit!
It's easy.
Seriously: it looks nice and all, but it's not carving; it's painting.