Stephanie Burgis mentioned them on Twitter.
They were apparently created to be a "great introduction to perennial classics both for very small children and parents who might never have read the classics before" and titles include Jane Eyre, Alice in Wonderland, Romeo & Juliet and the one I bought, Pride & Prejudice.
I really had no idea what to expect - how can you summarise Pride & Prejudice for toddlers? Well that's not really what the book does. It's a 'counting primer' so what we actually get is '1 english village', '2 rich gentlemen' [Mr Bingley and Mr Darcy], '3 houses' [Longbourn, Netherfield and Pemberley], '4 marriage proposals', etc., all the way up to '10 10,000 pounds a year' (which is a bit of a cheat, but made me laugh) all accompanied by simple, bright and retro illustrations by Alison Oliver.
I thought it was a cute and funny idea, but more suitable as a jokey present for a Jane Austen obsessive than something a child would be interested in. So I tested it on 3-year-old Joe (who is, I appreciate, probably slightly older than the target market, but I don't have any younger babies...). He seemed utterly baffled by the whole thing. He was slightly interested in the '7 soldiers in uniform' page, but apart from that, no. I'd still be interested in having a look at the other books in the series, but I don't think my toddler would.