That is the engine part. The explosive part separated.
And yes, it is horrifying. War, started by Russia, is horrifying. Murdering and torturing untold thousands of Ukrainian civilians is horrifying. Russia is a monster and will not be able to wash this off itself for the next 100 years.
I don't disagree with any of this. Assuming that was actually written on the missile and not after it hit the ground for propaganda purposes, the person who wrote it should be boiled in their own pudding.
Especially considering the love Russians and Ukrainians have for children. Even during Soviet Union, there was always a soft spot for children (as there should be).