First, insert a drag-and-drop question by clicking on +Add and selecting 'Drag-and-Drop Question.' The following steps will explain how to add an image as a drag component or as a drop target. For a general explanation about drag-and-drop questions, click here.
Adding an image in a drag component
1. Go to +Component
2. In the right column (the drag components), select an image
3. Search for or upload an image
4. You have now inserted an image as a drag component
Adding an image in a drop target
1. Click on the red button 'Drop Target'
2. Click on the settings cogwheel
3. Click on the pencil
4. Click on the 'Image' tab and select 'Upload Image' or 'Change Image'
5. You have now inserted an image as a drop target.