implies something easily hidden – in a desk, coat pocket, or briefcase.
: Like most mystery mail, it is generally a one-time play as materials may be altered. eng mystery mail the directors dirty little portable
The "Director" mentioned could be a prominent figure in film, a news producer, or a corporate leader directing a covert campaign. The "dirty little portable" suggests this director had something to hide, or perhaps, something they wanted to keep for leverage. Why would the director have a "dirty" portable? implies something easily hidden – in a desk,