Apple has announced that app screenshots will be locked in iTunes Connect once an app is approved. New screenshots can only be added when developers submit a binary for an updated to an existing or new app.
This move will help combat a common scam tactic that tricks people into buying fake apps with screenshots stolen from more popular or non-iOS games. Past examples include fake descriptions for various apps titled Halo 4 that were actually just a chess or racing game and a non-functional “Pokemon Yellow” app. Many scam developers managed to get past App Store monitors by using different screenshots when they first submitted their apps for approval and then later changing the store description.