Chevrolet 2010 Tahoe Owner's Manual page 85

Q: What is wrong with this?
A: The belt is twisted across the body.
2-46
WARNING:
You can be seriously injured by a twisted belt. In a
crash, you would not have the full width of the belt
to spread impact forces. If a belt is twisted, make
it straight so it can work properly, or ask your
dealer to fix it.