It's OK to reheat rice after cooking it.
You can put leftover rice in the refrigerator and then add a bit of water to the rice and then microwave the rice to reheat it.
Or add some ice cubes to the rice when reheating it as well.
The water or ice cubes help the rice stay moist so the rice does not dry out when reheating it.
Putting ice cubes in or on rice to reheat the rice does work.
Adding the ice cubes to the rice helps the rice stay moist when reheating it as the ice melts into the rice as the rice is reheating.
You can also add some water to a bowl of cold rice and it will too keep the rice from drying out when reheating it.
Basically the ice added to the rice just helps add water to the rice when it melts and makes the rice stay moist and heat up without drying out.
If you have rice on a plate then adding some ice cubes to the rice can help add the moisture when reheating the rice in the microwave.
Or if you have a bowl of rice you can add ice cubes to the top of the rice as well or just add some water which will accomplish the same thing.
I usually just reheat my rice in a bowl and add a little water to the rice to add moisture so it does not dry out.
Then I reheat the rice in the microwave for 1 minute which is usually enough.