While this trend isn't as widespread as one would expect, there are plenty of games on Steam that use concept art, pre-rendered cinematic images, or just plain ol' advertising material instead of actual screenshots from the game itself! Well, according to an image posted on the Facepunch forums (and subsequently confirmed by Valve) this little problem will soon be a thing of the past.
Once the Discovery Update 2.0 arrives in a couple of weeks developers of games with mature content will be able to pick and choose which screenshots to show based on the audience, but more importantly, the game's Storefront will be required to actually showcase in-game screenshots! Naturally, carefully engineered images and cinematic in-game screenshots are still fair game, but at the very least there will be no more deceptions. If you can see it on the store, you can see it in game as well!
Ironically, Valve's own Dota 2 was one of the biggest offenders as its Steam store page mostly featured gameplay screenshots from the closed beta and a couple of pieces of outdated artwork for characters that have long since underwent a redesign. The more observant among you probably already noticed that I used the past tense there, and this is because Valve decided to lead by example and be the very first developer to fix their own store page.
Much like a lot of games out there, I wouldn't say that these new screenshots perfectly represent what Dota 2 looks like for new players, but at the very least its a step in the right direction and one that I can definitely get behind. The one thing that worries me, however, is the simple question of who will enforce all of these new and upcoming rules? Valve has already shown they are heavily understaffed when it comes to handling the incredibly important customer service issues, so how exactly will they manage the time to deal with relatively meaningless screenshots? I honestly have no idea, but I guess we'll find out soon enough as the Discovery Update 2.0 is set to arrive in a "couple of weeks".
And if you're interested in the entirety of Valve's announcement and their reasoning behind each of the changes, here's the full post: