Why does my Yat page URL have random letters such as "%EF%B8%8F" in the middle of the emojis?
Not all browsers support the fully rendered version of all emojis completely quite yet. We know! It's outrageous.
When the an emoji that doesn't have the artwork available is entered into a browser, the browser still knows what the emoji is because it is instead rendered as code. So you will see some emojis correctly (usually the more common ones), with some rendered as code.
The good news is that as emojis grow in popularity, browsers frequently put out updates which include emoji packs. The random letters and codes will disappear! It can take some time, however and will depend on the browser/client.