The caricatured celebrities are, in order of appearance: Charles Laughton, Joe E. Brown, Joan Crawford, Irvin S. Cobb, Fred Astaire, Jean Arthur, Lionel Barrymore, Ben Bernie, Walter Winchell, Hugh Herbert, W.C. Fields, Katharine Hepburn, Ned Sparks, Lupe Velez and Johnny Weissmuller, John Barrymore, Harpo Marx, George Arliss, Mae West, Stan Laurel and Oliver Hardy, Clark Gable, Greta Garbo, Edna May Oliver, Gary Cooper, The Dionne Quintuplets, Groucho Marx, Helen Morgan, Wallace Beery, Edward G. Robinson, and George Raft.
The Coconut Grove was a popular celebrity hangout in the golden age of Hollywood. It was located at the posh Ambassador Hotel. At the time of this short, most famous night spots would broadcast a live radio program of dance music, as shown here.
The scene where a lady is revealed to be Groucho Marx was re-used in the later short, "Hollywood Steps Out," which was essentially a later re-make of this film.
Although the humor in this short might seem dated to modern audiences, it was contemporary at the time. In the days before social media (or even home TV broadcasts), most people relied on radio broadcasts and cinema newsreels to keep up to date on the latest goings on. Animation studios were quick to incorporate the latest celebrities into shorts like this, which was decidedly more adult in its humor.