The Christmas Apple Watch face is a holiday-themed face that features a snowy scene with a red and white theme. To get this face, you'll need to open the Apple Watch app on your iPhone and go to the Face Gallery. From there, you can search for "Christmas" or "Holiday" and you should see the Christmas Apple Watch face as one of the options. Once you've found it, simply tap on it and it will be added to your collection of watch faces. You can then set it as the active face on your Apple Watch.