On Wednesday, on the third leg of an unofficial three-day trip to Washington, D.C., Olena Zelenska, the wife of President Volodymyr Zelensky of Ukraine, became the rare first lady to address Congress.

But despite the fact that she had, on the initial two days of her trip, engaged in what could have been called typical first lady things — posing primly with Secretary of State Antony Blinken in his office; warmly greeting President Biden and the first lady, Jill Biden, who met her with a bouquet of flowers; wearing an array of dresses and suits by Ukrainian designers, with nods to the colors of the Ukrainian flag — she was not, as she said in her speech, there to talk about typical first lady things.

“Usually the wives of presidents are exclusively engaged in peaceful affairs,” she said as she stood in the Capitol in a black suit dress by the Ukrainian label AMG, a slice of white fabric bisecting one side of the jacket. “Education, human rights, equality, accessibility.”

Instead of all that, she said, she was there to ask for weapons, “weapons that will not be used to wage a war on somebody else’s land but to protect one’s home and the right to make up a life in that home.”

It was an emotional, unapologetic appeal, framed by photographs of the devastation in Ukraine, of children who had been killed, or maimed, and given extra power by the contrast between the familiar, soft-focus optics of the woman standing in front of the legislators and the harsh words she was speaking. The image was a reminder in black and white (literally) of just how much her job had changed because of war. That the “normalcy” of everyday life, as she said in her speech, was gone from Ukraine.

It was a reminder, too, that, just as in peaceful times, the role of the first lady is to act as the symbolic mother (and hostess) of the nation, she is still, in times of violence, its human face; the bridge between the familiar and the unfathomable.

In such a context, every choice a first lady makes, every gesture, becomes ammunition to be deployed on battlefield of public opinion, including what she wears. Especially, perhaps, what she wears, since for a first lady in her position, most viewers will not be party to her conversations with power brokers, but they can see the pictures.

They can recognize, for example, the “shared values” (as Ms. Zelenska termed them) between themselves and a civilian in the camouflage of a gently tailored skirt suit, in a way they might not connect with a soldier in actual camouflage.

It was obvious from the first day of Ms. Zelenska’s visit that she understood the mission, down to the smallest detail. Though it has become an unwritten part of the job that first ladies support local designers, to promote their business and profile on the world stage, her wardrobe strategy (because that’s what it is) went beyond simply boosterism.

Her olive green dress — strong shoulders, with an integral scarf at the neck — mirrored her husband’s signature uniform of olive green T-shirt, spoke to traditions of military clothing, and symbolized a refugee story, all at the same time. The designer, Lilia Litkovskaya (whose clothes Ms. Zelenska has often worn), had fled Kyiv with her husband and small child and is now in Paris where she has been promoting and supporting Ukrainian fashion from afar.

Ms. Zelenska wore a pin on the dress that mirrored traditional Ukrainian flower embroidery. It was from the Ukrainian jewelry line ​​Guzema, part of a collection called Nezalezhna, or “Independent”; her earrings were a pair she had worn for her husband’s inauguration in 2019.

She wore the brooch again the next day, when she met with the Bidens, this time on a light lemon yellow skirt suit by Ms. Litkovskaya, which she paired with light blue shoes, in a nod to her country’s colors.

(For anyone doubting that this was a bit of first lady pageantry, consider that for the photo op Dr. Biden chose a deep blue dress sprinkled in daisies, matched with bright yellow shoes. And that in a speech earlier this year at the Metropolitan Museum of Art, she said that for the State of the Union she had sunflowers, the Ukrainian national bloom, sewn on the sleeves of her blue dress because “I was sending a message without saying a word: that Ukraine was in our hearts — and that we stood with them.”)

And then there was Ms. Zelenska’s suit, for the speech to Congress. Against the soberness of the black jacket, the slash of white, covered in traditional Ukrainian embroidery, was impossible to miss. It was a pointed reminder beneath her words — “while Russia kills, America saves” — that, depending on what happens next, out of the darkness can come the light. A map of hope, worn on the body for all to see.