content: Digital photo files often contain 'EXIF' data that records e.g., the time the photo was taken, the camera model and settings like exposure time, apperature and ISO, etc. If the camera had an enabled GPS sensor, it might record the latitude and longitude of where the photo was taken. While the data isn't super apparent if you don't know about it, it's actually intended for use by the photographer and can be edited or removed pretty easily with the right tools.