The shapes are all the same width and they are “pressed out with a rolling cookie cutter,” according to McDonald’s Canada. The reason why they are all a standard shape and size is to ensure consistent cooking times for food safety in all McDonald’s restaurants, the company wrote on itsQ&A page.
But the varying shapes are also geared toward kids. “Our Chicken McNuggets are shaped uniquely for kids and kids at heart — it makes dipping more fun!” the company wrote.