Hey there @Sheepwall, unfortunately, I don’t believe Discourse supports collapsed content in the way you are looking. As you have likely seen based on the lack of page buttons, they are all about scrolling!
Edit: It seems Discourse is now shipping a plugin that should allow you to do what you are looking for. Just testing below:
Click here for an image[IMG]http://images.akamai.steamusercontent.com/ugc/581326799408662213/923795D51C91FE97BBEBCBF10C8F1DE39F16162E/[/IMG]
That was accomplished with the following code:
<details> <summary> Text to display at all times here </summary> Text/images to hide goes here </details>