Well then, just FYI, it's doing something different. Obviously lots of people are still able to see it, so it's not the end of the world, just wanted to give a heads up that there's been some kind of regression here.
They're showing as an external link for me (on liftoff) that I have to click through to display. Whereas previously they were an image directly in the post.
Looking at the URLs, both types of image are webp's hosted on sh.itjust.works, the only difference is the new ones have an additional format=jpeg parameter. I think the errors are on our side (ie the user's apps, not the uploader's), to treat these posts the same.