The website claims "All pieces created after January 26, 2013, are authenticated with Jodi Arias' right thumbprint."
Arias' drawings were selling on eBay in January, including one of legendary actress Grace Kelly.
Arias was an aspiring photographer when she was arrested in July 2008.
On Thursday, jurors were allowed to ask questions through the judge about psychotherapist Alyce LaViolette's testimony and the 44 hours she interviewed Arias in jail.
LaViolette, a domestic violence expert, testified that Arias was a victim of domestic violence.
The questions ranged from how the witness can know that Arias wasn't lying to queries about Arias' claims that the victim abused her.
LaViolette returns to the witness stand Friday for more juror questions.