A Virginia woman who lost her job with a government contractor after she was photographed extending her middle finger at President Trump’s motorcade last year has sued her former employer for wrongful termination.

Juli Briskman directed the gesture toward a string of black sport utility vehicles that zoomed by her on her bicycle on Oct. 28, as Mr. Trump’s motorcade was leaving Trump National Golf Course in Sterling, Va. Reporters and photographers in a car behind her captured the moment, which quickly spread online and became a source of many jokes on late-night television.

But Ms. Briskman’s employer, Akima L.L.C., did not find it funny.

When she returned to work the following week, she said, company executives told her she needed to resign. Ms. Briskman, 50, had violated the company’s social media policy on obscenity by sharing the image on Facebook and Twitter, they told her, according to the lawsuit filed on Wednesday in Fairfax County Circuit Court in Virginia.

The executives also feared blowback from the Trump administration, Ms. Briskman said the executives told her.