You could try taking the supporting image using a GPS camera app. This will attach a GPS stamp to your supporting image which will show the coordinates of where the photo was taken, and can be useful for reviewers to help ascertain that the location is valid (though it helps if you have other evidence to corroborate it). I asked about doing this in another thread and the ambassadors seemed to think it was a good idea:
Just whatever you do, don’t use the GPS camera app to take the main photo, as that will instantly disqualify it for having a watermark. It should only be used for the supporting photo.