The iPhone Steve Jobs revealed in January 2007 featured a 3.5-inch plastic display. Not many people remember that, because the phone sold that June was covered in glass. The switch from plastic to glass appeared as a footnote in an Apple press release just 11 days before the original iPhone went on sale. What happened in the five months between has mostly remained a mystery, until now, thanks to a video surfaced by Dave Mark at The Loop.

The story is suitably recounted by Jeff Williams, Apple’s Chief Operating Officer, who’ll also be responsible for software and hardware design when Jony Ive leaves Apple later this year.

As Williams tells it, the day after he held up the plastic iPhone on stage, Jobs complained to Williams about scratches that had developed on the iPhone’s display after carrying it around in his pocket. “We need glass,” said Jobs, according to Williams. Williams protested, saying durable glass wouldn’t be available for another three to four years. “No, you don’t understand, when it ships in June it needs to be glass,” replied Jobs, “I don’t know how we’re going to do it but when it ships in June it’s going to be glass.”

“Hey, your boss called and said my glass sucks.”

Two days later, Williams received a call from Corning CEO Wendell Weeks. “Hey, your boss called and said my glass sucks,” said Weeks, according to Williams. Weeks then suggested using technology “sitting on the R&D shelf.” The Apple and Corning “teams scrambled” over “months of sheer terror” to make the “hail Mary” work. The scratch-resistant glass that shipped on the first-generation iPhone would eventually come to be known as Gorilla Glass.

Williams’ retelling took place in 2017 at Corning’s factory in Kentucky where Apple announced a $200 million investment that’s likely helping to fund the company’s development of flexible glass for foldable displays. Apple’s rumored to be working on a device with a foldable display that could launch as early as 2020 — a product Williams is presumably intimately involved with.

Apple watchers have expressed concern over the future of Apple product design with the imminent departure of its Chief Design Officer. Stories have emerged of Jony Ive being ’dispirited’ by Tim Cook’s lack of interest in product development. Simultaneously, we’re seeing evidence that it’s been Williams who, despite his COO title, has been taking a larger role in product development. Notably, it was Williams who “led the development of [the] Apple Watch in close collaboration with the design team,” according to his updated Apple bio. Last week, The Wall Street Journal shared this little tidbit about Williams:

People who have worked with him say he has been more visible in the product-development process than Mr. Cook. Mr. Williams has shown interest in products’ look and feel.

Williams’ role in bringing a glass surface to the iPhone in 2007 helped shape the look and feel of every modern smartphone on sale today. The story paints a portrait of a guy who can manage the logistics of a supply chain, who’s also interested in making good products better. It’s part of a narrative that’s forming to position Williams as Ive’s natural successor inside Apple. More importantly, it’s also casting him as the heir apparent to Tim Cook.