Thanks to all that reply!
to mick:
i don't know where to find "separate file" in phone , i'm never aware it exists
both phone and gimp show a lot of info: Make, Model...
i don't know why location info is missing in gimp
to Eduardo:
cell phone shows street address in Chinese
i test your command:
$ exiftool -s image.jpg | grep '<part of the address shown on phone>'
it doesn't show street address
to all:
question i raise is much harder to solve than i expect
i give up
it's not very helpful even if it's solved
and i have other way to get around