Hello! Using Edge browser on https://lemmy.world I have attempted several times to upload this picture in portrait mode, but no matter the orientation of the picture before I upload, it always puts in landscape, rotated 90 degrees to the right. I tried it on both jerboa as well as through the site itself. Puzzling!
The only place I had it hosted was on Reddit, but I’ve deleted all of my posts on there, so not currently. Looking at the downloaded metadata, you’re right, it’s stripped all the metadata upon upload, which would explain it. To fix it, I copied the contents into a brand new .jpeg and that worked, as the orientation is inherent in the data then, instead of through metadata.