A Brogan is an event in which people see something horrid and frightening, usually they see something extremely graphic, like someone having a poo or getting plastic surgery because of ugliness.
Brogan is a word which can replace any word which related to disgusting, revolting, sickening, etc..
GUY: Oh my, I had some English homework to do last night.
GIRL: Wow, I bet that was a total Brogan event.
GUY: It really was.
GIRL: Did it resemble somebody going to the loo?