bent spark plug
 

https://cimg5.ibsrv.net/gimg/volvofo...69cd3e7a7.jpeg
what can cause if of thf sparks plugs to look like this?

Someone drops it before installation, or foreign material in the cylinder hits it.

Spark plugs are usually pre-gapped - so most are not in the habit of checking the gaps of every spark plug that's installed.