The pattern is:
Life smells like a roseVery nice indeed, we set up a happy comparison to life, and then explain how two people can fulfill it. Cool. Later on, we have:
With someone to paint and someone to pose
Life's a piece of pieAlso very nice. But then:
With someone to wash and someone to dry
Life is full of highsWhich...doesn't really rhyme, does it? The plural of "high" doesn't rhyme with "fry". Gee, how about "When someone stirs and someone fries"? Was that tiny change so hard to think of?
With someone to stir and someone to fry
Life's a leg of lambReally? Lamb/hand? Um, off the top of my head: "With someone to help you in a jam"?
With someone there to lend a hand
But then, the capper. Now the street vendors are making the "Life is" comparisons, and Gary and Walter are responding with spontaneous rhymes. But then as a punchline, they get stumped:
Life's a fillet of fishOkay, side issue, I'm wondering why they use the non-standard pronunciation "FILL-et" and not "fill-AY". But that's not the main problem. It's a funny gag and all, but:
Uh...yes it is!
A. If the gag is that they suddenly can't think of a rhyme, wouldn't it be better if, up to that point, they had been successful in thinking of ACTUAL rhymes?
B. What the heck's so hard about rhyming "fish"? "With someone to share your every wish" would work just fine. Or something with "dish". Instead, how about "Life's a juicy orange" or, I don't know, "Life's a dash of chutney" to set up the joke, using words for which rhymes don't IMMEDIATELY spring to mind?
It's like in "A Little Priest" from "Sweeney Todd". Mrs. Lovett is naming occupations (tailor, butler), and Sweeney is rhyming them (paler, subtler). All are perfect rhymes, of course. But then Mrs. Lovett says "locksmith", and Sweeney is stumped, and it's a funny moment because so are we.
Okay, while I'm at it, later in the same song Mary sings:
Everything's great, everything's grandExcept Gary's always off with his friend
Sigh. Two things:
A. "Grand" and "friend", of course, do not actually rhyme.
B. "Friend"? Seriously? Walter is Gary's BROTHER! I cannot think of any possible circumstance under which Mary would say "friend" instead of "brother". It's only there for the sake of the rhyme...which, of course, doesn't actually rhyme.
Okay, gripe over. I'm crawling back into my trash can now. I'll try not to let the lid bang.