How-Not-To-Train 101
Some people are amenable to following directions, while others are not so much. It’s safe to conclude that this person specifically chose this trainer to be strict with him since they knew that was the only way he would genuinely keep fit. Despite appearances, many people do better under pressure.
Perhaps taking a photo of their session and sharing it online is going too far, but who are we to judge? The student appears to be eager to finish his set, while his mentor seems to know what he’s doing. However, the man in the background is chuckling, and we don’t know why.