First, cut a big hole through the lid that is big enough to put your picture in it.
Secondly, Get as many puzzle pieces as you can and paint them red, pink white and other Valentine's Day Colors. Let Dry.
Now carefully glue the puzzle pieces to the plastic lid. Make one row complete circle of pieces and then let dry. Now, glue the rest of the puzzle pieces layering the first layer.
What you can do when finished: Add heart stickers, paint hearts or paint small heart candies on them.
Now, carefully cut the picture to fit the BACK of the lid and when dried, glue the cardboard piece to the back.
There is many possibility's to do this and its easy and fun.