Christopher Mesnooh, an American lawyer who works in Paris, said French law strongly protects privacy rights but tabloids have their own reasons for publication, even when they might violate the law.
"It appears to give satisfaction entirely to the royal couple," Mesnooh said of Tuesday's ruling.
But he added that the amount of money is nowhere near enough to dissuade the publication of similar photos.
"If you sell 100,000 copies, you're ahead of the game," he noted.
The ruling listed the royal couple by their full names: William Arthur Philip Louis Mountbatten-Windsor and Catherine Elizabeth Middleton.