LANE: A big shout out to Mama Kim on that one!
RORY: Look, Mama Kim always starts out super serious on everything but then lightens with time.
I believe this is the first time Lane’s mother is referred to as Mama Kim, previously she was just “Mrs Kim” or “Lane’s mom”. Mama Kim is the preferred fan designated name for her character.
Rory’s comment is further evidence that Mrs Kim is not nearly as strict as she likes to make out, and is capable of eventually changing her mind.