One of the Steam Workshop contributors for CSGO claims that his skin was changed after it was submitted for review, and that this change highlights a big problem with all AK-47 skins in the game.
The entry on the game’s subreddit showed an image from the AK Voltaic Steam market and compared it to how it looks in the game, and there are indeed a few differences. According to the user, the magazine is where the skins are changed the most.
Valve probably didn’t break all of the “Kalash” skins in CSGO
Fortunately, it may not be as much of a concern as the creator of Voltaic supposed. Steam Workshop developers frequently modify their designs by submitting them to Valve for review. Sometimes these final changes do not reach the image file uploaded with the skin, leading to some differences between the item file in the marketplace and its in-game representation.
In the past, this led to confusion with some weapons as the image files from the Steam marketplace did not match the in-game skins. But since CSGO skin makers donate their files to Valve, ultimately the developer has to update the photos from the market as well as the files uploaded in the game. Still, anyone who plays CSGO knows that sometimes Valve works its own way.
When developers update marketplace files, it is usually done in large batches, which explains the large lag between accepting the skin, putting it in the box, and selling it before the skin image is properly updated.
Of course, there are rarely situations where the difference between a photo on Steam and an in-game skin is significant. In addition, each skin from the marketplace can be checked before buying.