A trillion years ago when I was a wee tot I had a mug with a little mouse in it who would pop his head out to say hello when I was about half done with my cocoa. I'm glad to see that there is a classy adult version now that I'm an ancient lady.
Who doesn't love a surprise in their treats? Of course, when that surprise is a happy treat itself, not, like, a worm or something. Finding a heart in your cupcake is like finding a love note. It makes you feel special to know that someone cares enough to make a gesture.