In reply to Rania.

"For the uninitiated, “throwing sheep” is what people do on websites like MySpace and Facebook to get one another’s attention. It’s a “smiley” or “poking” someone online. Admittedly whimsical, throwing sheep is an image from the Gen V world of virtual social interaction. The “boardroom” represents the old world of institutional and corporate hierarchies that feels threatened by the potential consequences of these new social media. "

http://www.throwingsheep.com/about.php

At the risk of being rude, Rania, the above link was the first term on a Google search for "throwing sheep in the boardroom".