https://www.law.cornell.edu/uscode/text/18/713
I think this may be an election law violation.
Pull quote from article. The article has more to do with the blurring of the seal in videos and pictures but the principle is the same, see my emphasis below.
"The videos referenced (in the posts) were from President Biden's personal accounts, not the office POTUS accounts," Meghan Lee-Parker, an archivist at the Richard Nixon Presidential Library and Museum, said in an email. "Leaving them unblurred on personal accounts would constitute a violation of federal law as the use of the seal could be seen as advertising or campaigning."
In 1966, Congress passed a law to place restrictions on the display of the Great Seal of the United States. The statute was later amended to also prohibit the use of the presidential and vice-presidential seals in a way that could give "a false impression of sponsorship or approval by the government of the United States."
Thoughts? It may be worth a complaining to the FEC?