Technically, Sam is the head of the pack by virtue of being the oldest Alpha in the Winchester family. Bobby is the oldest Alpha, but he's not technically part of the Winchester line.

In most packs, it would mean Sam would have his own office, where he would make the decisions that concern the pack.

Instead, Sam comes out of the kitchen, drying his hands. The dishes still need to be done, after all. "Fantastic. I told you to leave that angel statuette alone." Ugly as it was, it had probably been worth a hell of a lot of money. "Go ahead and open it, then."