I am reasonably certain that that piece of ice is "timbering". It looks to be just stretching out as it slowly melts, and refreezes (which would explain how it formed) and that water drop (or the next) will just pull it apart.
That... doesn't look like it should be physically possible. Seriously. I was staring at it for five minutes before I realised no-one is that good at CGI and had to accept it was, in fact, real. Gorgeous shot, nice one
Physics much:
SHTOOBS