Ms Conway is seen clutching her phone as US President Donald Trump poses with leaders of historically black colleges and universities.
Twitter users accused her of "disrespect".
Ms Conway was taking her own photos at the time.
"That's no way to act in the People's Oval Office," tweeted one user of the social media site.
"Think of all the great people who sat on that couch and put your feet down," wrote another.
The images led some to question Ms Conway's body language, suggesting that she was not taking the meeting on Monday seriously.
Others downplayed the excitement, indicating that it was all a bit of a storm in a teacup.
The images of Ms Conway also drew comparisons to a photograph taken in 2013 showing then President Barack Obama with a foot up on the Oval Office desk.
"What a story. Hope Obama never put his feet up on the furniture," writes Kevin.
Mr Trump was meeting leaders of historically black colleges and universities to discuss his administration's support for the schools, including contracts and grants.
Ms Conway is no stranger to controversy. Earlier this month she was criticised after citing a "massacre" which never happened while defending Mr Trump's controversial immigration ban.
Her recent promotion of products linked to Mr Trump's daughter, Ivanka, led to calls for an investigation into whether she had violated ethics rules.
Senior White House adviser Kellyanne Conway has sparked a social media storm after pictures emerged of her kneeling on the sofa in the Oval Office with her shoes on.