By default, when you change the duration of a panel, the position of camera keyframes within that panel is adjusted to fit the new length of the panel. This behavior can be adjusted depending on your preference.
The Keyframes Sync Mode has three options:
None: When adjusting the length of a panel or a scene, the camera keyframes remain at their actual frames. This means that if you make a scene shorter than its camera movements, some of its last camera keyframes will get clipped out.
Relative to Panels: The default option. When adjusting the length of a panel, the position of camera keyframes within this panel will be adjusted to fit the new length of the panel. If camera keyframes are outside of that panel but inside the same scene, their distance relative to each other will not be affected.
Relative to Scene: When adjusting the length of the panel, the position of all camera keyframes within the scene in which that panel is will be adjusted to fit the new length of the scene. This could cause some camera keyframes to end up in a different panel than the one where they originally were. However, since camera movements occur at the level of the scene, not the panel, this option may give preferable results in some situations.