On an app
She said she puts hoisin sauce in her phở.
The line for this moment
You put hoisin sauce in your phở? I'll keep talking to you, but it's hard :))
The Vietnamese for it, how it sounds to an English speaker, why it works here and not elsewhere, and what she is likely to say back with what to do next: that is what the pack opens, for this line and the others like it.