More ice crystals on the window.  It only seems to happen when the humidity is just right.

They’re outside too (this one’s worth clicking on to enlarge):

These are birch trees.  Did you know that Bjørk, the singer, shares her name with the Icelandic word for birch?  At least, I’m assuming she does; it’s certainly the Norwegian word for birch, but maybe in Icelandic bjørk means cheese or volcanic lava. I don’t really know any Icelandic, I’m just guessing.