A classroom in Mexico City: hands shoot in the air. A nod sends one boy bounding to the digital board at the front, where he taps the nipple of a three-dimensional body image. There is a loud “ping” and a hyper-reality picture of the mammary glands is highlighted with such vigour it seems to jump out of the wall. The boy smiles and takes his seat and the class launches into a discussion about what different glands do.