The Not-At-All-Empty Vase
From The One with All the Jealousy
Phoebe: Oh my God, oh my God! Poor Monica!
Chandler: What, what, what?
Phoebe: What? He was with her when he wrote this poem. Look, (reading) 'My vessel so empty with nothing inside. Now that I've touched you, you seem emptier still.' He thinks Monica is empty, she is the empty vase!
Chandler: You really think that is what he meant?
Phoebe: Oh, totally. Oh, God, oh, she seemed so happy too.
Chandler is outraged. Monica Geller is many things. She is loud and overly competitive and compulsively anal and opinionated about everything except whether Picard or Kirk is a better captain of the Enterprise (if you ask her, she'll say Shatner was better looking but Patrick Stewart has a sexier voice. Chandler guesses she has a point, even though it's not really relevant to the question at hand). But empty? He can't even. She is full of love, and passion, and a profound need to do things (cook your favorite dinner, organize your sock drawer, fix your love life) for the people she loves. Monica is the least empty person he knows: she loves with everything in her, and the idea that someone could mistake that passion for emptiness just pisses him off.
If Chandler wrote a poem about Monica, it would be about crystalline blue eyes and soft freckled skin and raven hair. It would be about how fiercely she loves and how much she wants to take care of you – and how all she desperately wants is for someone to love her with some of the same focus and a fraction of the same care.
Chandler doesn't write poems, though: he makes jokes. So all he does is suggest to Ross that maybe he should give Monica the number of that barbershop quartet.