This is the advice I had a couple of weeks ago from a ticket from Anu......"About the ads with no visual content ("empty" ads), from now on, instead of skipping them, please rate them as best you can and when you reach the last question where you type in your freehand comment, enter a comment saying that there was no picture in this ad so you could not rate it properly. Unfortunately you don't receive compensation for skipped ads"
Just reopened my closed ticket from yesterday to inform that they are sending conflicting advice and they need to clarify this payment issue as it's not exactly fair.