It is unclear as to whether the press-materials were distributed by a publicity agency representing Ms. Hamilton or if they were distributed by an advertisement agency hired to publicize Maxwell House Coffee (represented in the second image seen on the right side of the uncropped photo).
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.