Much like the dungeon tiles, there are encounter images that return “403 Forbidden” errors. However, I think I figured out what’s happening on these.
(Again, I am not permitted to include links, so I am not including the domains in the paths below.)
A good example is Teron Gorefiend in the Black Temple raid.
If you look at /data/wow/journal-encounter/1585, you get a creature display reference like so:
If you look at that data from that reference, you see (among other things) a value for the zoom asset of: /npcs/zoom/creature-display-21262.jpg
That gives you the “403 Forbidden” error. However, if you substitute the encounter id in place of the creature display id, you see the image you expect:
I spoke a bit too soon, the other missing raid encounter images, Madness of Deathwing (encounter id 333) and Uu’nat, Harbinger of the Void (encounter id 2332) did not have that simple correction (still unsolved as of the moment).