These pics were taken a month ago as it was still sunny. The good days. :) Now it rains all the time.
It appears that these two lithops have developed seed capsules after flowering. They didn't have a partner except for each other. White and yellow don't mix with lithops but any mesemb pollen can occasionally induce selfing. If there are indeed seeds inside I'll keep them to sow someday when I have the room for such experiments.