Thanks for the reply and apologies for getting back to you. I typed that out right before going to bed :(
Looking in developer tools, it does look like Cloudflare is what’s blocking me. Here’s the cf-ray value: 8f4ffe74bffc22f1-ORD
Now that I’m on a PC, I can simply open the file in an image editor, resave it without making any intentional modifications, and the upload succeeds. It makes me think that it has something to do with the image metadata (maybe EXIF?).
I’ll send you a pm you a link to the unmodified image momentarily.
Very cool, thanks! This will make it a lot easier for me to post OC.