It has taken, apparently, not quite 65 years for anyone to notice what is perfectly evident in the still pictured: Raymond Chandler made a cameo appearance as "Guy Sitting Reading While Fred MacMurray Walks By" in Double Indemnity, which he co-wrote, adapting James M. Cain's novel, with director Billy Wilder.
Why did it take so long for anyone to notice? (Not that I ever did, in my I think three-ish viewings of the film.) That's obvs Raymond Chandler there. It's not like he's in a dress or anything.
Check back in 65 more years for exclusive stills of James M. Cain's cameo.