What should I do if I can't laugh when I take pictures?

When posing, photographers always say a little to the left and a little to the right. At this time, you don't need an expression on your face. Then you have to communicate with the photographer. You say, "You shout 3,2, 1, and I'll make a face, so that it won't be stiff." If you sit still all the time, he said, "Smile, smile, OK! If you don't move 3,2, 1 ",you will soon become stiff, right ~ If you don't move and he says" 3,2, 1 ",you will laugh, and this time will be more natural.