Hello, see
https://www.a7a10.net/forum/index.php?topic=19200.0"But now I’m not getting the choice of image size."
There has never been any choice about size, just the max file size is mentionned. See attachment.
Prepare your image on the pc \ tablet \ phone and make sure it's less than the max file size.
Anything from 1 mb \ 1000 kb to 2 mb \ 2000 kb is fine, but if needing specially detailed photos then go up towards 4 mb \ 4000 kb.
All phones will have some resize option, see attachment from my android\samsung. The 60% on that device gives me a filesize of a round 1,5 mb (down from approx 5 mb), still very large in pixels, around 1600 x 2800 and will look fine on any display.