The loss prevention associate does not take pictures of the person at all. I know this for a fact. They always wear plain clothes. They always call for backup when they are about to apprehend someone.
The other associates that are in the same position, but wear a yellow vest labeled "Asset Protection," are to show the presence of security. They can apprehend, and/or wear plain clothes, but mostly are to deter thieves who see them. They have a strong presence at the self-checkout area, where people try to get away with not scanning everything.
The apprehension can take place anywhere past the last point of sale. Which basically starts in the vestibule, if the LP associate decides to apprehend them there.