It's about the card backs that are pictorial but neither advertisements souvenirs (because I showed you the best advertisements, and none of the souvenirs are all that much to look at).
It turns out that the most elaborate pictures are of women or ships:
Well, apart from the butterfly.
The first two women and the second two women are obviously pairs from twin decks, as are the first two ships. I don't know what the woman wearing a towel is doing, but no way would she fit in that bath. The woman in the bottom-left corner is apparently Patricia from Royal Doulton; she therefore could count as an advertisement or a souvenir, but I put her here because my scanner can handle 5 cards in a row and it seemed a shame to leave one slot empty.
Also, thanks to QBlog reader Margarida S, who has better Google skills than I and found this web site, I can now cross two more off the list of unidentified manufacturers of common cards from my collection. It now looks like this:
I changed the second one along to Goodall, because that's who made it before it went to De La Rue and thence Waddingtons.
So now you can rest easy, at least until I buy some more cards that I like the look of (most of my attempts fail, though, so don't panic).