Debbie Reynolds' Catalogue Slap
At one point Debbie slaps Shelley Winters to bring her back to reality.
The slap is followed by a quick hug.
Darn if that isn't the exact same move that Debbie employs when - as Molly Brown - she slaps a fellow female passenger in a Titanic lifeboat in "The Unsinksable Molly Brown".
"Don't call me 'honey', mac."
"Don't call me 'mac'... HONEY!"