Hi, Jennifer! I guess this depends on if you are hoping to get a Christmas card photo that is stereotypically Walt Disney World, or did you want something holiday-ish?
You can get great Christmas shots any time of the year at the Winter Summerland miniature golf course at Walt Disney World. No matter what the calendar says, you'll find Santa (granted, he is surfing a wave), igloos, a chimney, and some very wintery scenes.
Another place people don't usually think of when taking a family holiday photo is the Christmas store in Downtown Disney. Disney's Days of Christmas shop has some stunning holiday decorations year round, and one of my favorite holiday photos of my girls is of the three of them standing in front of a wall of multicolored Mickey Mouse Christmas balls. I love it!
For something that speaks more to your vacation, you might do a photo in front of the Tree of Life at Disney's Animal Kingdom, or in front of the sorcerer's hat at Disney's Hollywood Studios. Stand by the Characters in Flight hot air balloon for something uniquely Walt Disney World in theme. For something a bit more fun, you could also do a photo in front of Splash Mountain or the Tower of Terror.
Consider the resorts as well. You'll get some amazing shots of Cinderella Castle in the background from the Grand Floridian and Polynesian beach. They make great holiday cards.
I hope you get the photos you are looking for!