You need to improve this. One of the disappointing things about this app is the "retribution". It is very normal for a user to ask for photos for those who don't have, and it is also normal for the other user to say that he will send with the condition that the other one sends first. So the user who asked for the photo sends his photo in the expectation that the other user sends his too. And it is very common that the user who said he would send his photo after receiving the other's photo simply does not send his photo. So a user shares hid photo expecting the other to send too and is either surprised with a block or just doesn't get any more answears, and this is pretty annoying. You could make a photo exchange invitation system, where each one sends their photo in an exchange option and they can only see theirselfes photos if both are present at the same time