I'm not sure if this has been talked about, but I just learned it. So it was new to me.
You can adjust the values/brightness on a smartphone (I use iPhone) when taking the pic by holding your finger against the image until it locks AE/AF. Then adjust a brightness slider next to the square in the center before taking the picture.
I attached two pictures taken in exactly the same lighting. One I adjusted the AE/AF lock lighter, and one where I adjusted it darker.
I didn't know this, others probably did.