Imagine the enemy unit is mostly behind some sort of cover, but a champion or a character is at the corner and not within/behind the cover.
If you target the unit, you would get the cover minus.
What happens when the HLR targets the character? Does the HLR still get the minus, because it's targeting a unit that is within/behind cover? Or can the HLR fire without the cover minus, because the HLR model can see the target model without intervening terrain?
This is theoretical, but can happen for example if the enemy unit hides behind a forest, but wants a mage to see your warmachine or similar.
-Zyg