When Joe Gillis says, "They'll love it in Pomona," most people assume (correctly) that Pomona is intended to be representative of just about any average American town. But it also alludes to the fact that Pomona was one of three towns in California's Inland Empire region (Riverside and San Bernardino were the others) that were frequently used during Hollywood's Golden Age for testing preview audiences' reactions to unreleased films. These towns were favored because they were on the way to Palm Springs, where, after collecting the audience reaction cards, studio personnel would then go to relax and determine what changes should be made to to the previewed films.
When Max is telling Joe about directing Madam's first pictures, there is a bad dub of the word "sixteen". After the Roscoe 'Fatty' Arbuckle trial and the subsequent establishment of the Hays Office to enforce the new Production Code, the producers were concerned that the original age of 14 would be considered child porn and had the line changed in post.
Norma Talmadge was the 'inspiration' for Norma Desmond, the grotesque, predatory silent movie queen in Billy Wilder's film Sunset Boulevard (1950).
One of the most popular sketches on The Carol Burnett Show was called "Nora Desmond" -- which was Burnett's send-up of Gloria Swanson's character Norma Desmond in Sunset Boulevard.