2 problems:
1. If a user by mistake choose a wrong photo it will be processed and add to photo module without even submitting it. There is an option to cancel it but it is processed too fast, it don't give the user time to think about it. So no reviewing before submitting pictures.
2. multi-uploader don't allow the users to select multiple files on mobile devices. you have to add pictures one by one. No tapping and selecting multiple pictures option.