– Standing before a full-length mirror in Neiman Marcus, I see double.

When I glance to the left, I find myself in a lipstick-red evening gown, with bolts of flowing silk cinched at my waist. I flick my eyes to the right, and I am all business, wearing a ­simple black dress topped with a patterned blazer.

These are not just the delusions of a giddy reporter playing dress-up on company time. I wasn't hallucinating — I was looking into a smart mirror.

The MemoryMirror device is not a mirror at all, but a screen projecting images captured by an overhead camera. The contraption, a recent addition to Bay Area Neiman Marcus stores, does much more than just show your reflection. It saves each outfit you try on, allowing you to compare different styles side by side to figure out which looks best.

If you're torn, you can share the images with your friends. And with the mirror's 360-degree view, you can scrutinize outfits from every angle.

The MemoryMirror device is the brainchild of MemoMi, a Palo Alto start-up. Since the mirror arrived in Neiman Marcus' Walnut Creek store in November and a San Francisco location last month, customers who have stopped to play with it have been delighted, said Scott Emmons, who heads the retailer's Innovation Lab.

Of course, the mirror also has attracted curious children and ­couples who preen in front of it like a photo booth.

"It's a selfie on steroids," MemoMi CEO Salvador Nissi Vilcovsky said.

Salvador came up with the idea for the mirror nearly a decade ago while working in fashion in Milan, but it wasn't until he met co-founder Ofer Saban that he was able to pull it off. Saban came up with key ­algorithms that correct the visual distortion that comes from the camera's placement above. Without them, customers would see themselves as bobbleheads, with oversize craniums and tiny legs.

I took the MemoryMirror for a spin on a recent morning. After standing before it in the drab dress I'd arrived in, I modeled a black blazer with flecks of white and that eye-catching red dress. I mulled the various combinations using an iPad, deciding which to display on the screen. (MemoMi places the devices on the store floor, rather than in dressing rooms, due to obvious privacy concerns.)

My verdict? The MemoryMirror just might come in handy for a customer like me. When forced to decide between two different items, I usually decide on impulse and live with the consequences. But with the Memory­Mirror, you simply toggle between snapshots of outfits you've already tried on.

MemoMi also has the bandwidth to project the outfit that you are wearing in every shade of the rainbow. And Salvador says it will change online shopping, as well. Once users have tried on an outfit with the MemoryMirror in stores, MemoMi can show them how they'd look in outfits they're perusing on the Web. That could be dangerous for those who already fight to resist the thrill of online shopping.