The effect that occurs when one severely unattractive fat person is with a group of good-looking counterparts. Once this person is noticed, no matter where you look within the group, your eyes will be slowly drawn back to that person.
Dude 1: "Check out those Hotties!"
Dude 2: "All I can see is that fat chick. What are you talking about?"
Dude 1: "Watch out. She's got Visual Gravity, man. Take a look at her hot friends."