Brynn Putnam has a lot to feel great about. A Harvard grad and former professional ballet dancer who opened the first of what have become three high-intensity fitness studios in New York, she then launched a second business in 2016 when — while pregnant with her son — she was exercising at home and couldn’t find a natural way watch a class on her laptop or phone. Her big idea: to install mirrored screens in users’ homes that are roughly eight square feet and through which they can exercise to all manner of streamed and on-demand exercise classes, paying a monthly subscription of just $39 per month.
If you’ve followed the home fitness craze, you already know these Mirrors quickly took off with celebrities, who gushed about the product on social media. Putnam’s company also attracted roughly $75 million in venture funding across several fast rounds. Indeed, by the end…