These cubes are made of plastic in different colors. They have water in the middle. They are frozen and served as ice cubes.
The melting ice does not mix with the drink. After melting, rinse them and put them back in the freezer. They are reusable.

Here are other pictures with these cubes.
https://steemit.com/frozenphotocontest/@jarosalawszafran/photo-fun-contest-week-18-frozen-photography-4

https://steemit.com/frozenphotocontest/@jarosalawszafran/photo-fun-contest-week-18-frozen-photography-3

https://steemit.com/frozenphotocontest/@jarosalawszafran/photo-fun-contest-week-18-frozen-photography-2

https://steemit.com/frozenphotocontest/@jarosalawszafran/photo-fun-contest-week-18-frozen-photography-1