Board Thread:Support Requests - Getting Technical/@comment-24916335-20150703202338/@comment-4018164-20150703205643

Well, no- though you can still put images as their URL (as long as the URLs are whitelisted, such as images from Wikimedia Commons or other Wikia wikis). You can, however, do that in gallery captions.

If the policy of the Avatar wiki, however, doesn't allow uploading images that are neccessary for articles, it might be a good idea to update the policy. You could ask the local admins to start a community vote about this topic, and explain what you want to add to the policy.