The new rule, made effective today, looks to stymie attempts from scammers who would submit an app showing one set of screenshots only to swap them out with images from other popular apps after being approved by Apple. As noted by MacRumors, nefarious developers would combine the fallacious images with app names suggesting the work was a legitimate iteration of an existing title.
A video of such a scam that has been making its rounds on the web shows an app called "Mooncraft," supposedly a a clone of the hit game Minecraft, is not quite what the buyer was expecting. As seen below, the screenshots in iTunes clearly represent a different game than the one actually purchased. Note that the Mooncraft icon is also a blatant copy of the Minecraft franchise, further confusing unwitting customers.
From the announcement:
While Apple's new policy will cut down on fake apps, it is also likely to hinder honest developers who will now have to go through the roundabout process of submitting updates to their respective app pages to change an image.
Beginning January 9, app screenshots will be locked in iTunes Connect once your app has been approved. New screenshots may be uploaded when you submit a binary for an update to an existing app or a new app. For more information on capturing and using screenshots, read the Xcode User Guide.