Is a girl sinful if a man accesses her account on a social media site and looks at the pictures of the girls she follows?

Accounts that contain immodest pictures of women should not be followed, because following them aids in the spread of those forbidden images. As for people who follow you and their accounts contain forbidden images, you must block them if possible. The default ruling for men following girls' accounts on social media is permissibility, unless there is forbidden communication or objectionable content. However, if the account owner posts forbidden pictures, then it is not permissible to follow her.