watermark is only working with words, it's not good. Everyone must enter everything wanted, words or pictures.....it's a personal choice, not your. sorry for my bad english, I'm french and love documentfoundation, it's a very good one. hope you'll enderstand my request
You can put images like a watermark. https://help.libreoffice.org/latest/en-US/text/shared/guide/background.html?DbPAR=SHARED#bm_id3149346 Also, you can put an image on the header, so it is visible on the pages with the same style. https://www.google.com/search?client=firefox-b-d&q=web%3Aask.libreoffice.org%2F+watermark