Did twine 2 remove the important image option? I used to use it before going to twine1 with sugarcube and it used to let you put images into the storymap itself.
I think so! At least I didn't see anything in the threads for Twine 2's rulebook. It said adding images was only doable through an external link using https:// and your local device using the like destination path of your hard drive. But with the local hard drive one I think it means that if the players don't have the exact same Pic saved in the same folder in their hard drive then there's nothing to display.
If I could just drag and drop art into twine it would be so much nicer
Maybe look into twine 1 as you can just drag and drop, also you can make the project bigger by linking multiple files so you don't have to worry about it becoming too big and it starting to lag due to the size. Don't mind helping if you need a complier if you're planning on doing extra. That way windows won't put a false positive because linking to a site without protection will set it off.