You're looking at the very first image ever taken of the shadow cast by one single atom. Researchers at the at Griffith University in Australia didn't even know if was possible for atoms to cast shadows like this until they tried it, but with some laser-cooled Ytterbium, a fancy lens, and five years of work, they were able to take this picture.
To get this to work, an atom of Ytterbium was cooled down to just a few thousandths of a degree above absolute zero in an ion trap. An illumination source was shined onto the atom, and on the other side of it was a fresnel lens that captured and focused all of the light that made it past the atom. The light that didn't make it past (that the atom absorbed) was what created that perfect little atom-sized shadow.
On a conceptual level, this is obviously totally cool, but there are a bunch of practical things associated with this research too. For example, using shadows to measure the locations of atoms and molecules is much less damaging and invasive than other imaging techniques, and it could be a way to track the behavior of biological samples (like DNA) without shredding them like X-rays and UV rays do.
Next, the researchers plan to put several atoms together in arrangements that mimic barking dogs and bunny rabbits, with the eventual goal of putting on the world's smallest shadow puppet show.*
*Sadly, as far as we know, the researchers are planning no such thing.