For the first time this millenium, the official obverse portrait of Queen Elizabeth II has been changed and the design chosen was done by 2014 proof Britannia designer, Jody Clark. The Royal Mint have released a couple of videos that are pretty informative and go through the history and the selection process.

The first video includes a brief interview with the designer of the new effigy, and the second briefly discusses the history of the use of the effigy on British coinage.