It’s just a touch more cross-season character stuff; Joan finds herself in the movies.
In Long Weekend, she is angry with Roger because she identifies with Shirley Maclaine in The Apartment. Later that episode, she says she needs to stop being Doris Day and become Kim Novak.
In Six Month Leave, Joan is again fully identified with an actress, this time, Marilyn Monroe. Although all the women are upset, it’s Joan who has to lie down. And once again, as in Long Weekend, she’s offended that Roger doesn’t get it.