system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 the unsettling feeling produced when looking down while on top of a tall building

And why is a similar reaction sparked even when viewing a picture taken from a high vantage point aiming down?
gpt
This is a really interesting phenomenon! Sometimes on the edge of a high place, you feel as though you're almost being pulled to it. This is because in your brain, alarms are going off everywhere (mostly in the amygdala, the part which processes fear) telling you that you are in danger, yet your brain's prefrontal cortex is also able to rationalize that you are not actually in danger. 

The conflict between these two processes creates the intense unsettling feeling.

TL;DR: Your brain thinks you're in danger, but knows you're actually safe, and has a tough time dealing with both of these ideas simultaneously.