Presumably this is a serious event - I could speculate that he's shielding his eyes from the glare of the lights, perhaps trying to spot someone in the crowd, but really, I've no idea what he's doing or why.

Piotr Snuss/Reuters
European Central bank Governor Jean-Claude Trichet attends a joint news conference following a summit to discuss the international financial crisis at the Elysee Palace, October 4, 2008.