Do you use Privacy Badger or another blocker?

The markup loads images from seemingly local URLs:

  http://data.simonschreibt.de/gat055/intro_comic.png

but redirects to images stored at SSL-ACCOUNT.COM:

  https://ssl-account.com/data.simonschreibt.de/gat055/intro_comic.png

I reset Privacy Badger, and the assets loaded fine.