I am a native speaker of U.S. English and was educated at a good prep school and Ivy League universities, but I am not sure what that sentence means. It may be obvious to someone who watches "Friends." I am guessing that one of the recurring jokes on "Friends" is that the characters do little but loll around in very comfortable furniture so if you buy similar furniture you can join the cast in spirit.
EDIT: The verb join has both literal and figurative uses. The literal meaning is to connect two or more things physically. The figurative meanings are about connections that are not physical: such as marriage, join together in holy matrimony. Sitting on a sofa will not make you be an actor in a TV show. Nor will such sitting on a sofa let you feel the actors (if you are weird enough to want to do that).
Connect has both figurative and literal meanings, but in its figurative senses it is usually phrased as connect with. That leaves join as the logical choice. It does not mean that the sentence makes any sense to someone not familiar with the show. In terms of meaning, the sentence should not be on an exam about English. It may be wonderful for an exam on American pop culture of the period.