The picture is an electron microscope shot of a snowflake.
It is pretty obvious if you think about it, but, just in case you are in a hurry:
Snowflakes all start in the shape of frozen water crystals, and at their most basic may be a simple hexagonal plate. But as a snowflake makes its way through the sky, the different conditions it encounters affect its growth. Dirt or dust particles can cause the pattern to alter, as can temperature and amount of vapor in the air. Lower vapor concentrations cause a snowflake to grow more slowly and produce less intricate specimens, while the lacey shapes we most associate with snowflakes are more likely to form in higher vapor concentrations, or in colder conditions such as those in high-altitude cirrus clouds. “Ice crystals take on more complex shapes—called polycrystals—in these low temperature and vapor concentration environments,” says Verlinde.
Totally irrelevant to the topic btu kind-of related to the article, an EM picture of an octopus larvae:
..and shark skin, baby: