Asta Nielsen was also the first screen Lulu, having played the character created by Frank Wedekind in the film, Earth Spirit (1923). Louise Brooks was well aware of Nielsen and her approach to Lulu, at least later during her life in Rochester, New York. It is not known if Brooks was aware of or made aware of Nielsen prior to her playing Lulu in Pandora's Box (1929).
I recently came across a German language booklet (on the Internet Archive) about Nielsen which contains some sublime images of the actress, including one of her as Lulu. She was certainly striking in her appearance. I would encourage everyone to learn more about this significant and too little known actress. (p.s. Nielsen had a role in the G.W. Pabst film, The Joyless Street, which set Greta Garbo on the path to stardom.)