This file depicts the coat of arms, banner, or emblem of Mexico, one of its states, municipalities, or any other political subdivision, or a similar distinctive symbol belonging to an international or "recognized" organization, or NGO, operating in or outside of Mexico. According to Mexican federal copyright law, article 14 subparagraph VII, these coats of arms/banners/emblems are not eligible for protection under the federal copyright law.
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 (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.