When you break glass, if you look closely, you can see the water in front of it (if there is any) disappear. The water is seen again after the glass breaks or when you stop breaking the glass pane.

I thought you could still see water when in the process of breaking the glass pane.

The water instantly disappeared and then reappeared.

Steps to Reproduce:
1. Have a glass pane that overlooks water.
2. Break it or attempt to break it
3. Look closely at what happens to the water.