The first cow is titled VACA PICADA – named for the cut tissue paper that is often used as a decoration in Mexico. 
The second photo is of VACA PICADA with the Torre Latinoamericana in the background.
From this skyscraper, the Latin American Tower, you can observe the whole city from the 42nd floor observation deck.
The third photo is of VACA PICADA in front of the monument Juárez Hemiciclo, built to honor President Benito Juarez. The Juárez Monument, also referred to as the Hemiciclo (hemicycle, or half-circle), faces Avenida Juárez. This monument commemorates the dead heroes of Mexico, with Juárez taking center stage.
The last photo is of VACA MARIACHI.
Mariachi is a type of musical group, originally from Mexico, consisting of at least two violins, two trumpets, one Spanish guitar, one vihuela (a high-pitched, five-string guitar) and one guitarrón (a small-scaled acoustic bass), but sometimes featuring more than twenty musicians. Mariachi music as we know it today originated in the 19th century.
Mariachis often wear a “charro” suit, a waist-length jacket and tightly fitted wool pants that open slightly at the ankle to fit over a boot. Both pants and jacket are often ornamented with embroidery, intricately cut leather designs, or silver buttons in a variety of shapes. A large bowtie, a wide belt and a large sombrero also often are part of a Mariachi outfit. http://www.sheppardsoftware.com/Mexicoweb/factfile/Unique-facts-Mexico17.htm
