Why isnt this garbo movie listed in any books etc

[Guest ariceffron]

MGM 1929- A man's man

She and johnny gilbert play THEMSELVES....

has any one herard of this and if so, why isnt it listed in any comprehensive books

[Rooster_Ties]

From the Allmovie.com (A Man's Man (1929)

Adapted from a 1925 play by Patrick Kearney, A Man's Man was popular MGM leading man William Haines' final silent film (albeit released with a musical score and sound-effects track). Haines is his usual bright-and-breezy self as Mel, a likable soda jerk in love with would-be actress Peggy (Josephine Dunn). Her head filled with the false words of self-styled talent agent Charlie (Sam Hardy), Peggy heads to Hollywood, leaving Mel behind. Our heroine manages to break into the movies and becomes a major star, but her heart remains with down-to-earth Mel. Greta Garbo and John Gilbert make "guest appearances" via clips from their previous MGM vehicles. — Hal Erickson

So it's just clips from some other movie (or movies) that Garbo had been in before. No biggie...