MIAMI, June 16 : Uruguay coach Marcelo Bielsa hit back at critics of his unusual pose in his official World Cup portrait, saying he owed no explanation to anyone for how it turned out.  FIFA commissioned photographs of all players and coaches ahead of the tournament for display on big screens at stadiums and on digital media. Bielsa's caught the 70-year-old Argentine with head bowed and eyes downcast, an unorthodox pose which proved hugely popular on social media and triggered a string of memes.