This is the Penguin Deluxe Classic edition of Shirley Jackson's last novel (but the first of hers that I read), the cover of which is illustrated by Thomas Ott.
If you are going to read it, I implore you to skip the introduction by Jonathan Lethem until you have finished the whole novel, because it contains many spoilers that completely ruin the experience of reading this book. I have had this happen a number of times and I really don't understand why publishers would include an introduction to a book that revealed the ending. It would have worked much better as an afterword. (I suppose I am in a position to actually get an answer to this as I work for the publisher in question. But I have not asked yet.)
That said, it is a wonderful, creepy, short book and the cover illustrations perfectly accent the tone. The french flaps are also quite lovely.