Actor Allusion: Azusa has one in the anime, though not to her seiyuu's previous roles but her previous job as a gravure idol. Azusa was asked to do a gravure idol audition and was asked to pose. Cue Male Gaze. On boobs.
Also in the anime, Haruka smacked herself in the face with a box lid on national TV. Her seiyuu had done the exact same thing on an online web show several years ago.