What architectural style is Norma Desmond's mansion in SUNSET BOULEVARD?

Just curious what the style would be. The main interior feature is the monster of a staircase:

http://houseandhome.com/sites/houseandhome.com/files/1_standout-staircases(1).jpg

The musical stage set is based on the movie version and a bit more garish:

Plenty of other pics are googlable.

Is this a particular style or just generic Hollywood gothic?

Rococo?

The second pic looks like something from H. R. Giger

The movie house was Spanish Revival. The stage set should include Max in Swiss Guard uniform.