Why this particular cover. I think this is the first in this series where Aggie’s name is her signature. This is has been quite standard in the last twenty years as part of her branding, giving the visuals a particular stamp. A signature edition, personally certified by the woman. And it throws up interest questions about how we view the signature in British media. Christie was a writer, a signature is the simplest piece of writing she would have done. Though it was not a signature she used often, after she divorced her first husband and took on her later married name one assumes her cheques would not have been signed Agatha Christie.
So don’t think that being armed with one of the signature covers, and a time machine, you can go back and diddle the Queen Of Crime out of her royalties.
This is also the first clearly branded Marple novel in this series, though the cover image is really quite subdued, perhaps as befits a book called Nemesis. This was snaffled fromt he Amazon French website so it could well be a French edition, though the A MISS MARPLE MYSTERY at the top suggests not.