Seeing images inside the editor?

I'm pretty new to twine, so forgive me if this is a stupid question. But when testing a page in the editor I can't get images to show. I had this typed in to test adding an image to a story.

Testing image

[img[images/test.jpg]]

I thought i was doing it wrong at first but after publishing it, and adding in the image folder to the same directory as the game it worked fine. I tried copy and pasting the images folder to the directory opened when you go to the menu on the top-left, Twine > Show Library, but no luck. Can anyone give any advice? I'm also using Sugarcube 2.0 if that helps.