I remember this 2014 piece about Rubik in Smithsonian (likely a Kottke link, haven't checked), in which Rubik describes the Cube as an object that “talks to human universals” while remaining “languageless.” It's compelling to think of it an example of a genre of grail-like universal design objects. Perhaps to have been included on the Voyager missions alongside the Golden Record (which shipped in 1977, two years after Rubik's initial filing with the Hungarian patent office)? Of course, like the Golden Record, it also is an indicator of organismic humanness, suggesting the scale and importance of a particular kind of manipulability.