I had this book as a child in the 90’s. It was a mix and match book with pictures of fantasy characters, and I believe there were 3-4 flaps that you could arrange to decide on their hat, face, torso, and bottom half. It was very obvious what the correct/incorrect options were, but they lined up well enough to make it a fun mix-and-match game. Each character was humanoid, but all fantastical.
There was not much text, but the basic premise was that these were all guests who needed to look their best for a party or wedding or something. It was a hardcover book with spiral bindings inside. The cover was white and had a magician, dressed in a purple domed hat, brown/black hair, a purple masquerade mask with frills on each side, and purple jacket while holding an orb I believe. The art style was very intricate and high fantasy. There was one page with a bride and a groom, and when they were lined up properly, their bodies formed a distinct heart shape. Towards the end, there was a king and a queen.
Unsure of publishing date – I had a copy of this starting in the mid 90’s at least, so it could not have been after that point.