GMC 2006 Yukon XL Owner's Manual page 42

Q:
What is wrong with this?
A:
The belt is over an armrest.
1-36
CAUTION:
{
You can be seriously injured if your belt goes
over an armrest like this. The belt would be
much too high. In a crash, you can slide under
the belt. The belt force would then be applied
at the abdomen, not at the pelvic bones, and
that could cause serious or fatal injuries.
Be sure the belt goes under the armrests.