Well this isn't always the case. I have upoloaded images to this forum that show up grainy and small and the same image on another forum and you can click to see a near-full res photo, both times using tapatalk. I wish I knew the answer but I suspect it's both the old forum app and an issue with the device app.
And it s seemingly random. The above pics are the same res on my iPad and yet this one is loading at 420 pixels.
Sent from my iPad using Tapatalk