It’s really simple. You have a Christmas ad to make. You look around at books aimed at young children and find something suitably sweet. You contact the author/illustrator and ask them to work with you in return for money.*
I’ve heard there is a fair amount of it available for the people who think up and subsequently make Christmas ads. I feel it’d be a nice Christmas touch to pay the author for their work.
It’s not quite so nice to steal someone’s creation and pass it on as your own, by saying that monsters under beds are so commonplace that no one, not even a former children’s laureate, can claim it’s actually theirs.
And when found out, it’d look a lot better if you admitted to making a mistake and offered a belated payment for the stuff you took.
Or, you could not. A bit like John Lewis and the monster under the bed, ‘inspired’ by Chris Riddell’s Mr Underbed.
If the Christmas ad was intended to spread goodwill and all those other things, I’d say it failed this year. If John Lewis wanted us to think nice thoughts about them, they also failed.
I’ll go and watch Mog’s Christmas again. That was a nice one. Judith Kerr was credited for her work. I suspect she might even have been paid for it.
*I’d be happy to make suggestions.