As unobtrusive as I've tried to make the addition of the sha1 to the thumb url, it seems to be throwing off Media Viewer.
Related Gerrit Patches:
|mediawiki/core : master||Extract file name from thumbnail only from first occurrence|
|mediawiki/vagrant : master||Enable CORS for Varnish|
|Resolved||Gilles||T121388 Service-based thumbnailing re-architecture in production with Thumbor|
|Resolved||Gilles||T111718 Service-based thumbnailing re-architecture on Vagrant|
|Resolved||Gilles||T118437 Make Media Viewer work with new URL scheme|