I am posting this here because the game module forum has been set to read only to deter spammers. I am using the latest game module code and Moodle 2.1.5+. If a question used in millionaire contains an image, the image does not render if the user clicks the 50:50, ask the audience, or phone a friend links.
This screenshot shows the question containing the image.
This screenshot is after clicking ask the audience. Notice only the alt text is shown.