In a segment that aired March 9 on NBC's "Rossen Reports," Jeff Rossen examined the mirrors and their affects on women's shopping experiences and ideas about body image.
"The clothes look better in the store than they actually do in real life so when I get home, it doesn't look the same," one shopper said.
The Skinny Mirror claims it "works on the psyche over time" and "gives users the instant visual gratification of a 'slimmer you' while educating that how you choose to feel about your body has nothing to do with your actual shape, size or weight."
The company, founded in 2013 by Belinda Jasmine-Bertzfield, produces mirrors designed to make one's reflection appear 5 to 10 pounds thinner. The Skinny Mirror claims the mirrors can boost stores' retail sales by up to 18 percent.
"It's really subtle," Jasmine-Bertzfield said of the mirror's effects. "It just gives you that little bit of extra hourglass."
Retail expert Andrea Woroch disagrees with the idea.
"Retailers will use skinny mirrors to deceive customers into looking a certain way when they try on their clothing," Woroch said. "The better they look, the more likely they are to buy something."
But Jasmine-Bertzfield said the mirrors aren't intended to only make people look slimmer. They're made to encourage greater body satisfaction.
"It's actually not about making people look good. It's about making them feel good," she said.
She pitched the idea on the television show "Shark Tank" in October 2015.
"I would love to have a mirror that made me look thinner in my home, (but in a store,) the customer doesn't know what they truly look like," said one woman who participated in Rossen's investigation.
Jasmine-Bertzfield said The Skinny Mirror was "first designed for the individual for personal use." The company's website says more than half of sales of the mirror "have been to individuals and homes." It wasn't until the mirrors gained attention that retailers began purchasing the mirrors for their stores.
To combat critics who say The Skinny Mirror is unethical and deceptive in stores, the company began marking the mirrors with their logo to distinguish skinny mirrors from regular mirrors.
The word "skinny" appears on the mirror in the bottom right-hand corner. The logo is smaller than the size of a pinky finger.