The media-ia and ia-media-patch branches on gitgud have been updated with pet play images relocated, so if you are using 2.2 pre-release / master-ia / master-ia-patch and update the game base, pet lesson images will be missing until you get the updated media too. If you don't care about the missing images, you do not need to update the media.
About that, there's been a slight mistake, a picture got renamed and shouldn't have.
The media branches shouldn't be downloaded until a few hours, the time Imperator connects again and confirms that this is okay.
As a precision, the links for the alpha version in the OP are always ultra the last version, it's a direct link to the last current version of the Git branch. Therefore, even if the date is late in the OP, the link would be the last, and thus if Imperator says in a post that a bug has been fixed, it will be fixed if you download it from the first post.