Is a Muslim woman sinful if she posts a picture of a naked disbeliever on a website, and is that considered as if she posted her own picture?

It is legally forbidden to post a picture of a woman who exposes her 'awrah (intimate parts), because it aids in unlawful looking and spreads indecency, whether the picture is of a Muslim woman or a disbeliever. Whoever does so is sinful, whether the picture is of herself or someone else.