David Ortiz is a member of the media during the World Series, as he's gone the route of another beloved Red Sox in Pedro Martinez and joined a postseason television crew. That means Big Papi has access to any number of things, such as former teammate Jake Peavy during his World Series press conference.
Obviously, Ortiz used said access in order to say hello to an old friend.
That's actually kind of adorable, especially after when Peavy just wants to talk about how great Ortiz is as a player and teammate. I'm glad the Sox were able to trade Peavy into another quality situation. The rumor is that he's going to buy a San Francisco trolley car to add to his 2013 World Series Duckboat should the Giants win, so now I hope he just keeps ending up on World Series teams until his backyard looks like a museum. The poor dude had to pitch for the Padres and the White Sox forever with nothing to show for either situation, so he's earned these chances.