There is also some data loss importing VW3 groups to platforms that don't have built-in social groups. This information should be saved until VaultWiki has a separate teams/groups feature: the group info, the members, the discussions, the group pages.
From VW3 and VW4 < 4.0.2, the group icon should be imported as the group page's icon. From 4.0.2 onward, the page icon would be used instead.
Still, there is no existing feature that could be used for social group pictures. These are pictures that are shared individually to a group. It is not possible for other group members to remove a picture that another user shared on the group, so to avoid regression, it would not be as simple as appending all the pictures to the group page content.
Rather, if there is anything similar, it's the Feeds feature. Feeds would need to be updated so that another kind of private feed is available, or that pages are allowed to have their own Feeds. For example, maybe a regular page could have a feed for related topics/pages.
While social groups, their members, and discussions can be fixed, this issue cannot really be closed until social group pictures are handled, which will require some improvements to the feeds feature.