Not my opinion, sorry, but one of the explicit criteria used in the selection process: one of the two had to be a woman.

To list the non-competence related criteria:
explicit:

• one man, one woman;
  
• one left-wing, one right-wing;
  
• the High Representative takes away the commissioner from its country of origin;
  
• some geographic balance, considering that the EP president is from Poland and the Commission President from Portugal/Iberia;

implicit:

• France and Germany did not want a Big Dick as president, and did not want to push names for either job;
  
• the UK seemed to absolutely want one of the two jobs;
  
• the small countries had a strong preference for the president to be one of them;
  
• the EPP wanted the President (and thus the High Rep would have to be from the left);

In the long run, we're all dead. John Maynard Keynes