The nation's first spouse, who often dons sleeveless attire, dared to show off her limbs in the picture that graces her Web site and was released Sunday.
"The sleeveless look is very much in keeping with what we've seen from Michelle Obama," said Politico White House reporter Malika Henderson of the first lady's black dress, which she set off with a white pearl necklace. "It is very much her signature look, so I wasn't that surprised."
But some are criticizing the South Side Chicago native for her choice of attire, calling it too informal and out of season.
And Obama's black dress with a strand of white pearls around her neck is just the most recent of her fashion choices that have featured her exposed arms.
Last week at President Obama's first congressional address, she chose a purple sleeveless ensemble.
"One reader summed it up better than most of them. She talked about how the season is winter, the occasion was business and a sleeveless dress was the wrong style at the wrong time," said Chicago Tribune style reporter Wendy Donahue.
She said the paper's Web site has received hundreds of online responses about Obama's outfit.
"Most of the complaints centered on the dress conveying a sense of informality on a serious occasion," Donahue said. "She's kind of faced some criticism for that in the past where people have said maybe [her clothing is] distracting from the central point, from what is going on."
Even some Washington insiders were surprised by Obama's wear because of the frigid February weather.
"When she was at the non-State of the Union address and had the sleeveless dress on, that was a bit of a surprise and I got some e-mails from some folks who were, you know, they work on the Hill and they were like, 'Wow she's sleeveless,'" Henderson said. "'Nobody else is sleeveless here and it is the winter.'"
First Lady of Fashion
Since Obama hit the campaign trail in support of her husband, the nation and its fashionistas closely have watched every style choice she has made.
"I think outside the Beltway people are just kind of fascinated with it," Henderson said of Obama, who is on the cover of this month's Vogue magazine.
The first lady of fashion has often drawn comparisons to Jackie Kennedy for her wardrobe, but not all of her choices have drawn positive responses.
Some panned the black-and-red figure-accentuating dress she wore the night her husband accepted the Democratic Party's nomination for president.
But one thing onlookers seem to agree on is that the first lady's fashion choices are a reflection of herself.
"She very much is her own person," Henderson said. "Her kind of philosophy of fashion is that women should wear what they are comfortable in."
"And so there she is with her arms out," Henderson said.
The Arming of a Nation
But even when critics can't agree on Obama's attire, they can agree on the state of her arms.
"She's very much proud of those arms. And she works out not only in the White House, she worked out before she gets up at 5:30 and works out with her husband," Henderson said.
And Donahue believes this won't be the last time Obama shows off her armed assets.
"I think it's clear she's going to make bare arms her signature statement," Donahue said. "And in many ways it's the perfect accessory for the times. They cost nothing except maybe a gym membership or a couple of 15-pound [weights] that you can use in your home."
"Those toned arms that are the envy of every woman, not just 45-year-old women, but 25-year-old women don't have arms that toned," she said.
There's even a Web site with workouts dedicated to getting Michelle Obama-like guns.