As has been mentioned in this thread by a few folks, I actually fall into the classic/old B&W movie style of things when you get down to it.
In a movie or a novel, a character can be killed and you don't need to see the wound or have it described (grabs chest and falls). A character can be tortured, but we don't need to see writhing agony as their skin is peeled...we only need to know someone hears the scream. Same-same for intimate moments; we don't need sweat and a detailed description of all 64 positions of the Kama Sutra, we just need a passionate gaze and fade to black.
I'll hedge on that here or there dependent upon what I'm writing and why I'm writing it, though usually just regarding the latter of those examples. However, that changes nothing...
A character is still killed, tortured, and made a happy face.
As to a current example...in my current effort there are scenes where not a few--but thousands--of people are killed in a single event. There is reason for it from all sides. So, with that aspect satisfied, that leaves the events. Even though I have the weapons detailed, I might state that 150 rounds are fired in three seconds of painting a crowd, but the most detail I offer is that 'people 3-deep fell in a wave.' The most gore I present in such a scene is 'a crimson fog hung in the air.' And though it
won't make sense out of context (sounding excessive, which it is not), the most cruelty I 'show' is the person who performed the mass-slaughter kick one of the wounded who begs her to kill them and states, "Shut up, you're dead. Wait for it."
I can think of no reason to describe what happens further than that within the story. The horrific nature of the situation is all too clear without any detailed description.
Anywho, as others have stated, the story itself--the whys--outlines why it's terrible and horrific. Just my opinion, but the detail is only needed if the story's reasons are lacking.
Just my opinion...
K2