Yeah that's what I thought too. The horrors are described well, they just typically don't get described through their physical form. As you say, because the human mind cannot comprehend it. There is a lot more focus on impressions, comparisons, and effects, rather than on a real physical description. Personally I thought it was quite neat!

Yes and also, people's reaction to the horror of often what gives it its punch. Like how the shark in jaws or even the alien in Alien are both good designs, but the actual reason they're so scary is because of how all the characters around them react to them.