Management guru Tom Peters’s adage—stick to the knitting—never reached the ears of small-business proprietors in Mexico. My first Spanish teacher interrupted lessons to take real estate inquiries. A lavanderia on Calle Jesús repairs small appliances. At an establishment on the Ancha San Antonio, you can get acupuncture—and while you’re at it, kidney dialysis.

Curiouser still, the sign on the left advertises kidney transplants. Storefront surgery?

I like the graphics: Robbie the Robot with tubes snaking under a masked patient’s smock.