Cosmas-the-Explorer 
Explorer in Training
[@Cinnamon Applecake](/images/3115791#comment_10918816)
Go to an Derpibooru image like this:
>>3115792p
Below source, you will find Share. Press it and you will get three options: Small thumbnail, Thumbnail and Preview. Small thumbnail is the smallest and Preview is the largest (I recommend Preview so one can easily see it.)
With any of these three options press Copy, than go to the Comment or Forum thread you wish to show it on, and press Paste.
Voila! You now have a clickable image. This feature of Derpibooru and Furbooru is allowing these easily clickable images.
If you need help I can show the image where you need to click.
Go to a
>>3115792p
Below source, you will find Share. Press it and you will get three options: Small thumbnail, Thumbnail and Preview. Small thumbnail is the smallest and Preview is the largest (I recommend Preview so one can easily see it.)
With any of these three options press Copy, than go to the Comment or Forum thread you wish to show it on, and press Paste.
Voila! You now have a clickable image. This feature of Derpibooru and Furbooru is allowing these easily clickable images.
If you need help I can show the image where you need to click.