An image quiz is a quiz that has a different background image for each question. To create an image quiz, just select any quiz that supports it (Yes/No, MCQs, Scenario, Open Ended) and select "Yes" on the button “Image Quiz” (shown below):
Once you turn on the switch , each question of your quiz will have an image icon that allows you to upload a photo. When you upload an image, a thumbnail of the image will be displayed instead of the image icon. See screenshot below:
To delete an image, just click on thumbnail and a trash icon will be displayed, allowing you to delete the image.