Hi Elin!
I'm so excited to welcome you back to the Disney Parks Moms Panel! Getting photos taken by the onboard photography team during our Disney Cruises is my favorite way to capture all the memories made on the ship! My family and I are sailing on the Disney Dream as I type to you, so I was able to stop by
Shutters: The Onboard Photography Shop and get information related to your great questions.
As mentioned in your question, one of the ways you can capture the memories from your Disney Cruise vacation is by creating a PhotoBook while onboard at one of the photo kiosks. They'll print the PhotoBook you designed and ship it to your home within four weeks of your cruise. The PhotoBook can hold up to 34 unforgettable photos from your voyage. The Cast Member onboard informed me that there is no copyright on the PhotoBook; you're able to take pictures of the pages of your book and post them!
Another option is purchasing a USB with your Disney Cruise photos on it. The digital photos come with a copyright release on the USB so you can take it anywhere and print pictures or create your own photo book on various online services!
In my opinion, having the USB with your cruise photos on it allows you to print as many pictures as you want (and even create a book by using an online service at home) whenever you want; I like the flexibility of the digital images on a USB drive. On the flip side, it would be very fun to create a PhotoBook onboard and receive your souvenir book in the mail after being home for a few weeks after your magical cruise. Another benefit to creating a PhotoBook onboard is there are special backdrops and pages offered on the photo kiosks that aren't available on the internet photo sites.
Elin, I'm wishing you tons of unforgettable pictures during your upcoming voyage!
Beth