The first reads..."THOUGH WITH THE DWARFS I LOVE TO DANCE, I LOOK TO YOU TO FIND ROMANCE. BE MY VALENTINE."
While it's difficult to see in this example, when you move the handle downward, Snow White and Grumpy's legs "dance".
Second card reads..."CHIPMUNKS AND SQUIRRELS AND ALL THE BIRDS ARE SENDING MY HEART WITH THREE LITTLE WORDS. TO MY SWEETHEART."
Move the handle downward and birds fly up to reveal "Love" message.
See a couple more heart-shaped mechanical cards in another Archive post.