wignu It's currently not possible, there is an extension to upload images to a thread. There is an outdated extension that allowed you to copy and paste an image that currently doesn't work and some talk of it being fixed see: https://discuss.flarum.org/d/2743-extension-for-pasting-content-rather-than-uploading/10
askjoyb i strongly believe some of the basic features need to developed quickly, so that people role this out in their website, that will help flarum as well.
SychO askjoyb You can use https://discuss.flarum.org/d/4154-friendsofflarum-upload-the-intelligent-file-attachment-extension
