Considering they are still images, the shots themselves are unlikely to contain much in terms of spoilers, unless you read Russian. That being said, it also means that there are people with access to a copy of the game, which may lead to full-fledged spoilers in due time. The sleuths over at Reddit speculate that the shots are possible with a physical edition of Horizon Forbidden West, and a jailbroken PS4. The argument is that physical games need to be sent to every corner of the world ahead of time to ensure that they are available on launch day. Because of this, the games are also made to be compatible with current firmware, and one future version without needing a patch. Overall, if you have strong opinions about spoilers, then it’s time to once again be careful on the internet. As mentioned, Horizon Forbidden West is only slightly over a month away from launch, on 18 February to be exact. (Source: VK, Reddit [1], [2] via Push Square)
