What is the ruling on a woman uncovering her shins and arms in front of other women only and having her picture taken, knowing that the film might be developed by a non-mahram man?

There is no harm for a woman in uncovering her shins and arms in front of Muslim women, as they are not considered awrah (parts of the body that must be covered). As for photography, many scholars consider it forbidden based on prophetic hadiths such as: "Every picture-maker is in the Fire..." and "Whoever makes a picture in this world, Allah will punish him until he breathes life into it...". The prohibition becomes even stronger if the pictures are of uncovered women and are viewed by non-mahram men, due to the violation of the command to lower the gaze and the spread of vice and corruption inherent in such actions.