The double-underlining is intended to alert the reader to the fact that it has been modified or affected by a later statement.
Readers are alerted to modifications through the use of double underlining.
There is no meaning behind the double underlining.
We don't pay attention to poor people.
The mat is green
Two people standing.
You are placing people's lives in danger.
Two people sit on a street bench together.
The Bay Area was the only affected area in the U.S.