Valve is making a huge change to their policy regarding what images developers can use in the Steam pages' screenshot section – they're requiring actual screenshots.
A message sent out to developers, revealed on Facepunch.com, details this decision. See the section concerning screenshots below.
The specific reasoning behind this is spelled out clearly: "When the 'screenshot' section of a store page is used for images other than screenshots that depict the game, it can make it harder for customers to understand what the product is that they are looking at."
This decision marks a consumer-friendly move for Valve in a post-No-Man's-Sky world, where everyone wants to know exactly what they're getting before they buy.
Valve also avoided accusations of hypocrisy by calling out their own Steam page for Dota 2, which included mostly artwork for their heroes. The Steam page for Dota 2 has already been updated, adding actual screenshots. While not specifically mentioned in the post, it does appear that cinematic videos are still kosher – as the message to developers only mentions cinematic stills and Dota 2's page still has their cinematic trailer.
