@Wopu - I've had YouTube videos simply display in a post. But with a picture, 🤔 I would assume that it needs to be downloaded to your device, and then uploaded to your post.

A standard URL is just a link to a page, and it wouldn't display the pic, because the pic is embedded in the page. But then again, it's been a long time since I've worked in IT. 💁🏻‍♂️🍻