Jerry Stiller (Frank) noticeably stammers and struggles to say "Del Boca Vista." Later, the clip show The Chronicle (1998) would reveal that he had great difficulty saying this phrase, ruining several takes by mispronouncing it.
In episode 5.2, The Puffy Shirt (1993), George (Jason Alexander) tells Jerry (Jerry Seinfeld) that his mother, Estelle (Estelle Harris), has never laughed, ever. Later in the episode the point is proven when Jerry attempts to tell her a joke and she's not interested. But in this episode, Estelle laughs at Jerry's joke: "Actually I'm drunk."
When Newman comes into Jerry's apartment to talk to Kramer and him about the shower heads, you can see a wedding band imprint on his left ring finger. Wayne Knight had recently got married at this point. In one scene in a previous episode, The Seven (1996), he was accidentally wearing the band.
De la Boca Vista translates to "View of the mouth."