What is this for (Earth maybe)

[GCusdin]

I have a wiring loom bracket removed from the engine at prestent and have the below under the bolt that goes up to my bolt for the ignition coil.



Without the bracket I can't help feeling something is missing. It looks like an ground point but for what?
Nothing seems to have gone wrong since it has been off.
Anyone know what it is for and why it goes from my coil bolt to the end of the cylinder head?

[lee gsi]

Its probably to help stop interference