Nice website - thanks!

I did find this on the website, under the "20 Copyright Facts" section. Specifically, #19...

"The use of preexisting material in a work does not change the copyright status of the preexisting material. If it was copyrighted, it still is. If it was in the public domain, it still is."

Unless I am mistaken, does this mean that if a photograph in public domain is printed in a copyrighted book, the photograph itself is STILL PUBLIC, but not the rest of the book?