Hieroglyphs doesn't appear
The main problem is that the src attribute used in img HTML elements are relative (starting with /), making the browser request to Wikiwand.com server. Since there's no serving hieroglyphs in Wikiwand, the image does not appear. I suggest something like a RegExp replacement in the string consumed from Wikipedia. This should fix the relative path to an absolute path (i.e.: https://en.wikipedia.org/w/extensions/wikihiero/img/hiero_O1.png?39788)
I could do that if I had access to code, is it open source? Thanks!