Here's why:
* The Couch: The iconic orange couch in Central Perk is a central element of the show.
* The Boat Picture: There's a framed picture of a boat hanging above the fireplace in Monica and Chandler's apartment. It's a running joke that Chandler's father, who never stuck around, was always sailing away.
While the boat picture is not as prominent as the couch, it's a recognizable element of the show's visual identity.