yes, the webUI appends a ?format=webp to the image load request, but I assume the conversion fails. Clients that don’t try to get burggit to convert it but take the original image can load it just fine. .jpeg is treated weirdly in general, it is also cached on the instance even if the original source is elsewhere, and the links still get the ?format=webp as a result. So even uploading to shota.nu won’t fix it, but converting to png will