CK: ... "James story and the wonderful film "The Innocents". The way I read the "T of the S" is open-ended. I do not see any resolution of the ambiguity. However, I would certainly be open to thinking about a possible resolution. The one in the film is only a suggested interpretation - - it still retains and allows the occult explanation of events - - most beautifully and convincingly envisioned, I might add." [...] I thought picadillos did mean tiny sins - - or does it have something to do with bull-fighting? LC called them "portmanteau words" didn't he?

JM: When I first watched the movie, as a little girl, I only grasped the occult explanation.The story left a deep imprint in me and, if not Jane Eyre but certainly "Wuthering Heights" ( with L.Olivier) made its mystery become even the stronger. Those Brontë sisters, Poe... childhood terrors and delights. Yesterday I could only see  the lovely hysterical governess, with a lot of imagination and power, beginning to interpret random noises, pauses, innuendoes, school reports and tempests to build a frightening suspense in the end, but no ambiguity like I'd found it in the novel. Perhaps I'm mistaken but, as Molière once said: "Les premiers sentiments sont toujours les plus naturels." and this is also valid for a Pale Fire  more traditional interpretation ( a novel I didn't read as a child...).  Yesterday, in truth, I felt a kind of kinship bt. Kinbote's delusions and the interpretations made by  governess's and it caused me some discomfort, as if their kinship was extensive to me when I try to plum-pick in excess.  

There is the picadilly collar, the London circus, an armadillo protection ( I wish the bulls could wear armor ), the picadero (the guy that spits the bull, bull-ring, riding-school, lover's nest).
The "tiny sin" as "pecadillo" may have no relation to SK-B suggested Greek word for a diminutive is present not  in "pic" but in "dillo" (or "illo").