Face-covering and fitnah

So, I know there is debate about whether Muslim women should cover their faces. From my research: - In the Hanbali madhhab, the dominant opinion is that **covering the face is obligatory** in the presence of non-mahram men, as the face is considered part of a woman's awrah. - **The other three schools**: The Hanafi, Maliki, and Shafi'i madhhabs do not generally regard the face as awrah, and so they **don't consider it obligatory to cover the face**. However, scholars typically say **that if uncovering the face leads to fitnah, then it becomes obligatory to cover it. ** My question is: What does fear of fitnah mean? Who decided whether uncovering the face leads to fitnah? Does that mean if a woman thinks men might be attracted to her, she should cover her face? or is this expected in certain environments?