Here’s how I think that went down:
Director Zack Snyder: “Here’s your cake, sweetheart!”
Director Zack Snyder’s Daughter: “But, Daddy! I just wanted a pretty unicorn cake! Why is Yoda on there??”
Director Zack Snyder: “Did you pay for this cake, or did Daddy?”
Via the Star Wars Blog, who just wanted a pretty Yoda cake, and somebody stuck a stupid unicorn on there.