it's one of a set and they hark back to graphic designs of some earlier versions, which pleases me.
https://www.penguin.co.uk/series/smiley/the-smiley-collection.html
(one of these things is not like the others... in fact there's a whole nother series with those pale blue covers, identical apart from the book name)
― koogs, Tuesday, 19 January 2021 22:23 (three years ago) link
(penguin website run by penguins judging by the speed of it)