imgur has figured out how and when it's safe to redirect PNG/JPG requests to a "JS blob" (of advertising), unfortunately. They tried to pull this a few months ago, completely bungled <img> embeds, and had to turn it off in a hurry. I think they've figured it out this time, sadly!
Time for a new image host... imgur has gone all high-level and "scale"-ey, it would seem (particularly with the new video with sound thing).
I was going to say something about toxicity, but this is sadly just a scaling problem. Now that sound - and competing with youtube - is the new "major consideration", just being a competent works-anywhere image host has been relegated to the region of rounding errors, so it doesn't matter in the same way if they get that right anymore.
Also, they're detecting that I'm on a mobile browser and forcing a redirect to a smaller version version of the file with _d appended to the filename. If this were a large file, I would not be able to see the full size without something like changing my user agent.
