While taking the selfie, the displayed image is mirrored so you can line things up easier. This is demonstrated in the first image.
After the photo is taken, the image is unmirrored and displayed naturally. This is demonstrated in the second image.
I'm a little confused by what you mean by reality getting reversed.It may help if you lrovide pictures.
You may be changing the orientation of your device causing your camera to assume which way is up and down.
You may have a orientation lock on your device as a whole, that is affecting the camera
You might just be seeing your ...