In order to use Advanced Actions to show or hide objects such as images you need to be able to reference the Item Name of the object. Objects on Master Slides do not have Item Names, so you cannot show or hide them that way. You need to place the objects on the slides themselves, give them a unique Item Name that helps you to find them in lists (e.g. change from img2 to img_Fred), set their Visible in Output to OFF, and then you can potentially use Advanced Actions to SHOW the images.
However, your next issue will be that on Question Slides you only have a few events you can use to trigger Advanced Actions. You can trigger an action via the On Slide Enter event of the slide, but that only applies BEFORE the user has answered the question correctly or incorrectly. The On Success and On Last Attempt events are the other events you can use and these fire AFTER the user has answered the question, but only AFTER the learner has clicked for the second time to quit the Feedback Captions on that slide.