Grace Meng said she believes that sending the image was her husband's way of trying to tell her that he was in danger.
She added that she has had no further contact with him since the message was sent on 25 September.
Ms Meng also said that four minutes before Mr Meng shared the image, he sent a message saying "wait for my call".
"His job is very busy," she said. "We connected every day."
French police launched an investigation into the disappearance of Interpol‘s president after he was reported missing after travelling to China.
Chinese authorities have said that Mr Meng is under investigation for unspecified violations of the law.
Ms Meng would not speculate on what might have happened to him. Asked if she believed that he has been arrested, she said: "In China, what happened, I'm not sure."
She read a statement during her press conference in Lyon but would not allow reporters to show her face, saying she feared for her own safety and the safety of her two children.
Mr Meng, who is a Chinese government minister, was lives in Lyon with his wife and children, is also China’s deputy minister of public security.
He has also previously served as head of the country’s counter-terrorism office, drugs control commission, and coast guard.
His term as Interpol’s chief is due to run until 2020.