How to change the order of images in the Media Library
To do this, click on 'Cases' in the navigation bar.
On that case, click the 'Select category' dropdown menu and choose 'Media Library':
Click 'edit' next to the Media Library you want to edit. This takes you to the category manager of the media library. You'll see a list of categories: A gear wheel will only appear behind a category when there are no subcategories. If you do not see a gearwheel, but do not have a subcategory: delete the empty subcategory and the gear wheel will automatically appear.
Click on the gear wheel and drag & drop the images in the desired order. Hit 'Save' when you're done and click 'Close' to close the pop-up.