Someone with more knowledge may correct me if I'm wrong, but 121034 was previously owned by the Birmingham Railway Museum, who presumably fitted the destination blind, as it does have destinations relevant to that place on it. Presumably for authenticity, they fitted a blind that, besides those stations, also has all sorts of destinations that the units would really have worked to on it — many in Wales, many on the Great Western, and plenty of other peculiar ones. It certainly wouldn't have been a blind fitted when it was in "real" passenger service, as it has such a variety of destinations as to be ridiculous for that!