Because the camera has a special watermark. According to the information of the query card rice network, when the watermark option in the mobile phone photo album setting is turned on and the photos taken by the mobile phone camera are saved in the photo album, watermarks such as personal signatures will appear in the lower left corner or the lower right corner of the photos. The content of watermark can be changed, which has the function of decoration and anti-theft map. If you don't need a watermark, you can turn it off in Settings of the system album.