My wife wants to add photos with a back pose on instagram. What do u recommend to allow or not since face is not visible and the clothes are not fit and not exposing body parts.

As long as the face is not showing, the clothes are loose and appropriate, then it should be fine. My recommendation is that it should not be a pose that is catchy or draws attention. The reality is, if a man sees the photo and the pose is catchy, then this would violate the laws of modesty. So just make sure it’s not catchy.