It’s not entirely clear, but it seems likely that Ro’s admission about her dad isn’t something she feels comfortable talking about with Julia. However, she’s able to tell two complete strangers about it, highlighting the important role that strangers can play in a person’s life. This admission then allows Roger a moment to connect, as he sees himself in Ro. So, he’s able to step into the role of Ro’s dad for a moment and tell her that the apartment really is fine—and that she, Julia, and their baby will also be fine.