Apple’s executives had a critical design decision to make about the company’s riskiest product in years. It was 2019, and a growing team of Apple engineers had been working for more than three years on a headset that combined augmented and virtual reality capabilities. Now they had to figure out whether the mixed-reality headset would be a stand-alone device or would require a powerful base station to produce the dazzling digital imagery Apple envisioned for it.

Apple CEO Tim Cook and then–Chief Design Officer Jonathan Ive were among the executives who viewed VR demos on prototype headsets that simulated how the two approaches would differ, according to two people familiar with the demos. The headset that worked with a base station had superior graphics, including photorealistic avatars, while the stand-alone version depicted its avatars more like cartoon characters. Mike Rockwell, the Apple vice president in charge of the company’s AR/VR team, favored the headset with the base station, believing that Apple’s top brass wouldn’t accept the stand-alone version’s lower-quality visuals, according to the two people.

He was wrong. Ive had pushed for the stand-alone version of the headset since the early days of the project, according to a person familiar with it. Ultimately, Apple’s senior executives sided with Ive. Despite that, Rockwell still assured them he could make a great product. The choice has had lasting repercussions for the repeatedly delayed headset, which goes by the internal code-name of N301.