(CNN) She wears a wide smile, perhaps mid-laugh, as she sits on a couch next to a smiling boy. Their hands clutch remote controls to a video game. Their eyes reflect shared joy.

In the digital painting, artist Nikkolas Smith captures the "final, joyful moment" of a 28-year-old aunt who was gunned down in her home this month by a police officer in Fort Worth, Texas, who'd been summoned for a welfare check.

"I wanted to paint the last thing pre-Med graduate Atatiana Jefferson was doing before she was killed by the cops," he wrote in an Instagram message posted with his artwork.

Rather than capture Jefferson's killing -- for which the officer has been charged with murder -- or the community protest that's followed, Smith aimed to "show the humanity of the victim," he told CNN on Tuesday.

His perspective has struck a chord.

The Photoshop painting of Jefferson even was shared at poster size on the floor of the US House of Representatives. The congressman who spoke alongside it echoed a message Smith shared in his social media posts: "I guess we can add this to the list of things black people aren't allowed to do at home," he wrote. "Her Life Mattered."

Channeling change through 'the power of art'

For Smith, 34, focusing on Jefferson's final, beautiful scene reflects the message he hopes his art gives to the world, he said.

"I've seen firsthand some of the ... worst of what we think of in terms of being singled out for just having black skin," he said. "I just feel like, in a way, my art is kind of a tool to fight that. I want to use my blackness to bring a different point of view."

Smith opted to mention Jefferson's academic credentials in his social posts to illuminate an often-ignored facet of African-Americans' lives, he said. She graduated in 2014 with a pre-med degree in biology from Xavier University of Louisiana and was working in pharmaceutical equipment sales.

"I don't want it to be qualifier, like her life mattered more because she was educated," he said. "But that's something that's not often highlighted in terms of black lives."

For Smith -- himself an uncle who diapered, then later played Xbox with his own nieces and nephews -- seeing his art displayed at life size on Capitol Hill via C-SPAN was "a surreal moment," he said.

"I didn't imagine anyone blowing my artwork up that way," he said. It drove home "the power of art. And to see how he was using it to really call for police reform, it was unbelievable."

It only took three seconds, THREE SECONDS, before a Fort Worth police officer fatally shot #AtatianaJefferson in front of her nephew.



We have to hold our law enforcement accountable and fix the systematic failures that have brought us here today. pic.twitter.com/wkFUT1XzVx — Rep. Marc Veasey (@RepVeasey) October 16, 2019

Allies can simply 'share this art piece'

The Jefferson image is among the latest in Smith's Sunday Sketch series, a six-years-and-counting project by the artist to create a digital painting over just a few hours on the first day of every new week. Also part of the series are images of former NFL quarterback Colin Kaepernick taking a knee and the Obamas cast as superheroes.

Smith has considered calling the project a wrap, he said, but then hears from people who are moved by his pieces. "Somebody said to me, 'If you stop doing these, who's going to do them?'" he said.

Smith's works often aim "to say: We are all on the same team, we're in the same boat, we're all one human race." They also can serve as a vehicle for anyone who might struggle to find the right words to share the values his pieces convey, he said.

"I think one of the biggest messages is to say to white people, you can be an ally in this fight with us," he said. "You can use your voice to speak out. And sometimes, it might be as simple to share this art piece. If you feel like you don't have the words to say, just share this art piece, to show people that you are standing in solidarity."