dartrax in the past I included most of the library in the dist file in an effort to avoid external resources, but this was a futile effort - The emoji images are already loaded from that very same CDN and there's no way to change that setting.
So I might as well load the picker library from it as well.
As discussed previously in this thread, embedding the emoji images in the extension would be unrealistic.
Flarum already loads all its emoji images from a CDN, so the issue isn't specific to this extension. Only difference is Flarum uses MaxCDN, while the picker uses jsDelivr.
I'm still hoping to release by new redesigned Emoji extension in the future, which will include an option to customize the CDN, with an option to point to a locally hosted emoji set.
As said many times before, this extension is a low-effort integration of a library I didn't create (EmojiOne Area) into Flarum. Which means we are limited by the design of that particular library, which is a simple jQuery plugin with few options.