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.
:(