Adaptation Displacement: Most people think of the 1953 film, but don't even know it was originally a musical or a book.
Harsher in Hindsight: Lorelei asking if three sleeping pills in the straight vodka is enough. Most people know how Marilyn Monroe died.
Ho Yay: Dorothy Shaw can't find a man who satisfies her needs, is very snarky with all her beautiful friend's suitors, and only declares her love for Malone when it becomes clear doing so will benefit Lorelei. Interesting... Then there's the double wedding in the final scene - the cinematography tends to cut the grooms out of frame, making it look like it's the two women who are getting married.
I Am Not Shazam: Several people who are familiar with this movie but have never seen it think the title is "Diamonds Are A Girl's Best Friend", after its famous musical number.
Sequelitis: But Gentlemen Marry Brunettes didn't get the two leads back, so it tried being about their daughters.
Strawman Has a Point: When confronted about her unabashed gold-digging Lorelei gives a pretty cogent speech pointing out that a man would want his daughter to marry into wealth, so why she shouldn't want that for herself?