Question about nuscenes camera2lidar extrinsic

[lucianzhong]

For one scenario in nuscenes dataset, take 61 as example, the sensor2lidar_translation between CAM_FRONT and lidar_top differs from one timestamp to another timestamp.
such as: [-0.01613824 0.43552529 -0.32067179], [-0.00871988 0.5708719 -0.31998898]
0.5708719 - 0.43552529 = 0.13, the y direction of translation is the vehicle's forward direction.
From my opinion,the extrinsic should ideally remain constant or minor variation.
Could someone give explanation?

Best regards