What do you mean by changing to a concert?

This sentence means taking photos or videos of idols on behalf of fans at concerts, thus making profits.

The existence of body double photography is based on fans' pursuit of star idols and their desire for exclusive content. Some fans can't come to the concert site because of time, place and other reasons, or want to get more professional and high-definition photos and videos, they will choose to take pictures instead to meet their own needs.

Acting photographers usually use professional photographic equipment to get exclusive photos and videos by crouching and tracking, and then sell them to fans in need at a certain price.