They aren't frozen, the are just for the decoration. I don't have a picture, but they are shaped like a small cube. I know there are web sites where you can purchase them. I know this because during a trip two years ago DD (with autism) fell in love with hers and carried it everywhere with her during that trip. We got about three of them that trip and they lasted about two weeks (with almost constant use). After that, I went on a mad search for them.
They come in a wide range of colors and some just tap on/off. Others will blink.