I think it's safe to say by now that this is indeed an intentional homage as it's not only mentioned in several TV sites (like this or this and also TVTropes), but it's also now on IMDb:
In Episode 6, Xanthippe's female friend is finishing a story with the punchline "...and then she stepped on the ball." This line, the context and the pompous "Yuppie-esque" delivery, are borrowed from a similar scene in "Trading Places" (1983). Which in turn borrowed it from Auntie Mame, the Rosilind Russell classic from the 50s.
It's both a thematic allusion (Xanthippe's hipster-looking friends are really no less preppy and snobbish than the ones in Trading Places) and a pop-culture reference that's expected from a Tina Fey series - especially when it's from a classic 80s comedy that featured SNL members so prominently.