Where does my publisher logo appear in my exported book, and why is it missing?
The publisher logo is printed on the title page of the book: in the PDF and the ebook, and from version 1.9.24 in the Word (DOCX) file too. It comes from the author profile the book uses. To check, open the book's page, then Book details, and look at "Author & publisher": the logo is the one of that profile. Press "Manage profiles" to open the Authors page, choose the profile and add its "Publisher logo" (save the profile first if it is new). Then export again.