The first three pictures show the process. This first picture is right at the start when the bubble is beginning to freeze. You can see the beginning of frost spots.
The same bubble then burst. You can still see the outline of the air that was in the bubble.
You can also see the fragments of ice as it explodes. These three pictures were all of the same bubble, taken one after the other.
The next bubbles give a clearer picture of ice forming on the bubble.
Sometimes the sun started to melt the bubble before it burst. As you can see in this next picture, this bubble is starting to collapse and actually has a hole in it.
The last one is probably one of my favourites. You can see the ice starting to form on the bubble, and the bubble is still clear enough that it has the reflection of the porch in it. There is only one porch railing, but it is reflected in the bubble twice.
Isn't it interesting how God has made frost, and the way it works?