The ADD-ON fee is a once off fee for the Christmas Themes. Even if you have multiple pets, you only need to purchase it once at $5. If you want more than one digital pet sketched, just add the extra pet fee option instead.
So you've already ordered a Digital Sketch from me in the past or have a new one in your cart, but now you would like to add the Christmas in July's theme!
After your purchase, just email me your pet's name & insta handle and I will use your old sketch with the current theme/theme of your choice! Let me know what theme you would like.