Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title

In Raul Ruiz's Le Temps retrouve, a crowd in chairs listens to a chamber music performance. At times, while the camera pans around the audience, rows of people slide left & right. For examples, in the clip linked just above: at 0:33, the front row slides to left; at 1:37, the second row slides to the left; at 1:47, the second row slides to the right; at 1:54, the second, third, and fourth rows all slide; at 2:07, the front row slides to the right; and at 2:24, both rows slides to the right. Why does the crowd slide around like that?
Why is the audience sliding around in this scene from Le Temps retrouve?

In Percy Jackson & the Lightning Thief, How can Percy and his friends play all the games in the Lotus Hotel casino, when they are still teenagers and the legal age for the gamble in Las Vegas is 21?
How can Percy and his friends play all the games in casino?

After seeing Men in Black III, I still don't understand why K became such a cranky, stoical figure. It is a question even Agent J was puzzled about!
What happened to Agent K to make him so grumpy and emotionless?