Some previews in the image gallery report the wrong Content-Length

On Chrome, the preview disappears after the request times out, even though the entire image was loaded.

On Firefox, the tab just shows a loading icon for longer than normal.

I've found three so far that have this problem:

• https://www.bodyinflation.org/node/21593
• https://www.bodyinflation.org/node/21740
• https://www.bodyinflation.org/node/21737

On the first image, the content-length for the original is 198008, but the preview's is 210887.

The browser thinks the preview image should be bigger than it is, and keeps waiting for the site to send more data until the request times out.