A NY Times article about the pope recounts his early papacy:
At first, he was stiff.
Giovanni Maria Vian, the editor of the pope's newspaper L'Osservatore Romano, recalled that in the early days Benedict used to greet crowds with an awkward victory gesture "as if he were an athlete.""At some point someone told him that wasn't a very papal gesture," Vian said. Benedict changed course, opting instead for an open-armed embrace or an almost effeminate twinkling of his fingers on an outstretched hand as a way of connecting with the crowd.
And with this move, I guess he wasn't stiff anymore. Hey, I didn't write it; the Times did.