Wiktionary claims that it's a fixed expression, but doesn't actually have the page.

Fönstret står på vid gavel och uppkrupen i fönstersmygen sitter en tjej och röker.

The English translation has the window "wide open", and the girl "huddled on the ledge", incidentally, but according to what I've been able to determine, she's actually in the "nook of the window". Is this right?