The trailer, Diego notes, opens with the voice of a Chihuahua called Papi describing how his descendants fought alongside Aztec soldiers, then pans to footage of Machu Picchu in Peru--a symbol of the Incan Empire located on a different continent. The music in the trailer is mambo, which originated in Cuba, he adds.
A viral video campaign (with no mention of Disney or the movie title, in today's fashionable stealth style) has elicited groans for its portrayal of Chihuahuas as revolutionaries declaring "No mas!" to being carried in purses--but "Mas!" to all-you-can-eat taco bars.
For more on the subject, see Racist Chihuahua Trailer and Indiana Jones and the Stereotypes of Doom.