What does flash mean?

A brief introduction to the story of Flash

Jun Yong, the boss of a small company that deals in cameras and monitors, had a little trouble with his 26th birthday. Girlfriend MengMeng runs an underwear online shop, works from home every day and rents out houses to make money. Recently, MengMeng recruited a new tenant as a photographer, named Shen Wei. Shen Wei was generous and rented a house in MengMeng at three times the price. In the face of this simple and ignorant girlfriend, Junyong is full of anxiety. He warned not to believe what Shen Wei said and to keep a distance from each other. In the process of tracking Shen Wei, he found that the other party seemed to be secretly filming others. Junyong tried to convince his girlfriend, but MengMeng also asked Shen Wei to help her take promotional photos of underwear models.

One day, Junyong sneaked into the photographer's home and installed a camera in a key corner. Before the screen, a strange scene appeared in front of him. ...