Assumptions are treacherous — just ask Lululemon about Mirror

Rita McGrath
5 min readMay 22, 2023

In high uncertainty situations, one can obviously make decisions that turn out not to be so great. But seriously, do you want to be the CEO featured in a headline “How A Ballerina Outmaneuvered you”?


Here’s a story about a global pandemic, companies trying to make business sense out of an unprecedented behavioral shift and the sense of urgency that can sometimes cloud decision-making.

The next iPhone — the gateway drug to your future fitness

Mirror was very much of the moment — a virtual, programmable interface that was just a wall-hung mirror when not in use but turned into a programmable magical window when turned on. Mirror itself had a bit of a buzzy past. Brynn Putnam, the charismatic founder of the business had a big, big vision.

As Medium writer Maya Kosoff recounts, “We always said that we believe we’re building the next iPhone,” she had told Fast Company late last year.

Fitness, in other words, was only the gateway drug for the Mirror to become the content delivery system for anything else virtual. “We’re building the third screen in your life,” she said. The possibilities were endless — telemedicine, fashion, therapy. Putnam had raised $74.8 million from VCs, along with celebrity customers…



Rita McGrath

Columbia Business School Professor. Thinkers50 top 10 & #1 in strategy. Bestselling author of The End of Competitive Advantage & Seeing Around Corners.