I used plastic molds to create the shapes and applied the correct pressure at just the right point to achieve these wonderful pieces. Well, the dog liked them really well.
The first piece was a half moon semi-circle like a chunk of longhorn cheese from your supermarket. The water froze completely across my dog's circular pool. I stepped on it right in the middle just barely applying any pressure and it snapped the circle of ice almost cleanly in half. Then I removed the semi-circles from pool and stood them up by the storm cellar entrance. A giant 4 foot diameter by 3/4 inch thick ice sculpture of cheese glistening in the sun.
The second piece was from a 2 quart water pitcher that I left on the patio table last night. It did not quite freeze completely leaving a small section of liquid at the bottom of the pitcher but still frozen on the sides. I turned the pitcher upside down and the chunk of ice came splashing out. I put it upside down on the ground and filled it with water for my dog. He drank from it. And wagged his tail in approval.