Do report out of date pictures. We might not get to unapproving posts immediately, but we will look at the reports. The classifieds rules ask for a "current date" in the picture, that means when you list something on May 14, it should have May 14 timestamp in the picture (could be a day or two old, but still basically the same date as the post). Some posts with timestamped pictures end up being bumped for a month or two, we could add a bit about updating photographs periodically if an item doesn't sell for a long time.