Why is the seal upside down?

Maybe you are taking a selfie! When taking a selfie, the text in the photo is reversed, which is generally divided into two situations:

1, mostly occurs in the film period, because after taking pictures, the film should be developed first, and then the negative image on the negative film should be projected onto the image paper with a magnifying glass for amplification and development. If you don't pay attention to the reverse side of the negative, the developed photo text will be reversed.

2. During the period of digital photography, the number of reflections will be greatly reduced. If the characters are photographed directly, they are all positive, but if they are processed by later software, they will sometimes be mirrored like film, and the characters will become negative.